diff --git a/client/src/__locales/en.json b/client/src/__locales/en.json
index 18eabbce..66541f0f 100644
--- a/client/src/__locales/en.json
+++ b/client/src/__locales/en.json
@@ -223,6 +223,8 @@
     "anonymize_client_ip": "Anonymize client IP",
     "anonymize_client_ip_desc": "Don't save the full IP address of the client in logs and statistics",
     "dns_config": "DNS server configuration",
+    "dns_cache_config": "DNS cache configuration",
+    "dns_cache_config_desc": "Here you can configure DNS cache",
     "blocking_mode": "Blocking mode",
     "default": "Default",
     "nxdomain": "NXDOMAIN",
@@ -529,5 +531,17 @@
     "rewritten": "Rewritten",
     "safe_search": "Safe search",
     "blocklist": "Blocklist",
-    "milliseconds_abbreviation": "ms"
-}
\ No newline at end of file
+    "milliseconds_abbreviation": "ms",
+    "dnssec_enable_desc": "Set DNSSEC flag in the outcoming DNS queries and check the result (DNSSEC-enabled resolver is required)",
+    "cache_size": "Cache size",
+    "cache_size_desc": "DNS cache size (in bytes)",
+    "cache_ttl_min_override": "Override minimum TTL",
+    "cache_ttl_max_override": "Override maximum TTL",
+    "enter_cache_size": "Enter cache size",
+    "enter_cache_ttl_min_override": "Enter minimum TTL",
+    "enter_cache_ttl_max_override": "Enter maximum TTL",
+    "cache_ttl_min_override_desc": "Override TTL value (minimum) received from upstream server. This value can't larger than 3600 (1 hour)",
+    "cache_ttl_max_override_desc": "Override TTL value (maximum) received from upstream server",
+    "min_exceeds_max_value": "Minimum value exceeds maximum value",
+    "value_not_larger_than": "Value can't be larger than {{maximum}}"
+}
diff --git a/client/src/components/Filters/Form.js b/client/src/components/Filters/Form.js
index 46e0579d..0237a5d6 100644
--- a/client/src/components/Filters/Form.js
+++ b/client/src/components/Filters/Form.js
@@ -3,8 +3,8 @@ import PropTypes from 'prop-types';
 import { Field, reduxForm } from 'redux-form';
 import { Trans, withTranslation } from 'react-i18next';
 import flow from 'lodash/flow';
-
-import { renderInputField, required, isValidPath } from '../../helpers/form';
+import { renderInputField } from '../../helpers/form';
+import { validatePath, validateRequiredValue } from '../../helpers/validators';
 import { FORM_NAME } from '../../helpers/constants';
 
 const Form = (props) => {
@@ -28,7 +28,7 @@ const Form = (props) => {
                         component={renderInputField}
                         className="form-control"
                         placeholder={t('enter_name_hint')}
-                        validate={[required]}
+                        validate={[validateRequiredValue]}
                         normalizeOnBlur={(data) => data.trim()}
                     />
                 </div>
@@ -40,7 +40,7 @@ const Form = (props) => {
                         component={renderInputField}
                         className="form-control"
                         placeholder={t('enter_url_or_path_hint')}
-                        validate={[required, isValidPath]}
+                        validate={[validateRequiredValue, validatePath]}
                         normalizeOnBlur={(data) => data.trim()}
                     />
                 </div>
diff --git a/client/src/components/Filters/Rewrites/Form.js b/client/src/components/Filters/Rewrites/Form.js
index 5382ee32..2db7be35 100644
--- a/client/src/components/Filters/Rewrites/Form.js
+++ b/client/src/components/Filters/Rewrites/Form.js
@@ -3,10 +3,8 @@ import PropTypes from 'prop-types';
 import { Field, reduxForm } from 'redux-form';
 import { Trans, withTranslation } from 'react-i18next';
 import flow from 'lodash/flow';
-
-import {
-    renderInputField, required, domain, answer,
-} from '../../../helpers/form';
+import { renderInputField } from '../../../helpers/form';
+import { validateAnswer, validateDomain, validateRequiredValue } from '../../../helpers/validators';
 import { FORM_NAME } from '../../../helpers/constants';
 
 const Form = (props) => {
@@ -34,7 +32,7 @@ const Form = (props) => {
                         type="text"
                         className="form-control"
                         placeholder={t('form_domain')}
-                        validate={[required, domain]}
+                        validate={[validateRequiredValue, validateDomain]}
                     />
                 </div>
 
@@ -61,7 +59,7 @@ const Form = (props) => {
                         type="text"
                         className="form-control"
                         placeholder={t('form_answer')}
-                        validate={[required, answer]}
+                        validate={[validateRequiredValue, validateAnswer]}
                     />
                 </div>
             </div>
diff --git a/client/src/components/Settings/Clients/Form.js b/client/src/components/Settings/Clients/Form.js
index 65c16cb3..5c7bf471 100644
--- a/client/src/components/Settings/Clients/Form.js
+++ b/client/src/components/Settings/Clients/Form.js
@@ -13,13 +13,12 @@ import Tabs from '../../ui/Tabs';
 import Examples from '../Dns/Upstream/Examples';
 import { toggleAllServices } from '../../../helpers/helpers';
 import {
-    required,
-    clientId,
     renderInputField,
     renderGroupField,
     renderSelectField,
     renderServiceField,
 } from '../../../helpers/form';
+import { validateClientId, validateRequiredValue } from '../../../helpers/validators';
 import { FORM_NAME, SERVICES } from '../../../helpers/constants';
 import './Service.css';
 
@@ -48,12 +47,12 @@ const settingsCheckboxes = [
 const validate = (values) => {
     const errors = {};
     const { name, ids } = values;
-    errors.name = required(name);
+    errors.name = validateRequiredValue(name);
 
     if (ids && ids.length) {
         const idArrayErrors = [];
         ids.forEach((id, idx) => {
-            idArrayErrors[idx] = required(id) || clientId(id);
+            idArrayErrors[idx] = validateRequiredValue(id) || validateClientId(id);
         });
 
         if (idArrayErrors.length) {
diff --git a/client/src/components/Settings/Dhcp/Form.js b/client/src/components/Settings/Dhcp/Form.js
index 6e0a134f..6fd8c40e 100644
--- a/client/src/components/Settings/Dhcp/Form.js
+++ b/client/src/components/Settings/Dhcp/Form.js
@@ -4,11 +4,9 @@ import PropTypes from 'prop-types';
 import { Field, reduxForm, formValueSelector } from 'redux-form';
 import { Trans, withTranslation } from 'react-i18next';
 import flow from 'lodash/flow';
-
-import {
-    renderInputField, required, ipv4, isPositive, toNumber,
-} from '../../../helpers/form';
+import { renderInputField, toNumber } from '../../../helpers/form';
 import { FORM_NAME } from '../../../helpers/constants';
+import { validateIpv4, validateIsPositiveValue, validateRequiredValue } from '../../../helpers/validators';
 
 const renderInterfaces = ((interfaces) => (
     Object.keys(interfaces).map((item) => {
@@ -96,7 +94,7 @@ let Form = (props) => {
                                 name="interface_name"
                                 component="select"
                                 className="form-control custom-select"
-                                validate={[required]}
+                                validate={[validateRequiredValue]}
                             >
                                 <option value="" disabled={enabled}>
                                     {t('dhcp_interface_select')}
@@ -125,7 +123,7 @@ let Form = (props) => {
                             type="text"
                             className="form-control"
                             placeholder={t('dhcp_form_gateway_input')}
-                            validate={[ipv4, required]}
+                            validate={[validateIpv4, validateRequiredValue]}
                         />
                     </div>
                     <div className="form__group form__group--settings">
@@ -137,7 +135,7 @@ let Form = (props) => {
                             type="text"
                             className="form-control"
                             placeholder={t('dhcp_form_subnet_input')}
-                            validate={[ipv4, required]}
+                            validate={[validateIpv4, validateRequiredValue]}
                         />
                     </div>
                 </div>
@@ -155,7 +153,7 @@ let Form = (props) => {
                                     type="text"
                                     className="form-control"
                                     placeholder={t('dhcp_form_range_start')}
-                                    validate={[ipv4, required]}
+                                    validate={[validateIpv4, validateRequiredValue]}
                                 />
                             </div>
                             <div className="col">
@@ -166,7 +164,7 @@ let Form = (props) => {
                                     type="text"
                                     className="form-control"
                                     placeholder={t('dhcp_form_range_end')}
-                                    validate={[ipv4, required]}
+                                    validate={[validateIpv4, validateRequiredValue]}
                                 />
                             </div>
                         </div>
@@ -179,7 +177,7 @@ let Form = (props) => {
                             type="number"
                             className="form-control"
                             placeholder={t('dhcp_form_lease_input')}
-                            validate={[required, isPositive]}
+                            validate={[validateRequiredValue, validateIsPositiveValue]}
                             normalize={toNumber}
                         />
                     </div>
diff --git a/client/src/components/Settings/Dhcp/StaticLeases/Form.js b/client/src/components/Settings/Dhcp/StaticLeases/Form.js
index 9cbbb0a2..40854f6e 100644
--- a/client/src/components/Settings/Dhcp/StaticLeases/Form.js
+++ b/client/src/components/Settings/Dhcp/StaticLeases/Form.js
@@ -3,10 +3,8 @@ import PropTypes from 'prop-types';
 import { Field, reduxForm } from 'redux-form';
 import { Trans, withTranslation } from 'react-i18next';
 import flow from 'lodash/flow';
-
-import {
-    renderInputField, ipv4, mac, required,
-} from '../../../../helpers/form';
+import { renderInputField } from '../../../../helpers/form';
+import { validateIpv4, validateMac, validateRequiredValue } from '../../../../helpers/validators';
 import { FORM_NAME } from '../../../../helpers/constants';
 
 const Form = (props) => {
@@ -31,7 +29,7 @@ const Form = (props) => {
                         type="text"
                         className="form-control"
                         placeholder={t('form_enter_mac')}
-                        validate={[required, mac]}
+                        validate={[validateRequiredValue, validateMac]}
                     />
                 </div>
                 <div className="form__group">
@@ -42,7 +40,7 @@ const Form = (props) => {
                         type="text"
                         className="form-control"
                         placeholder={t('form_enter_ip')}
-                        validate={[required, ipv4]}
+                        validate={[validateRequiredValue, validateIpv4]}
                     />
                 </div>
                 <div className="form__group">
diff --git a/client/src/components/Settings/Dns/Cache/Form.js b/client/src/components/Settings/Dns/Cache/Form.js
new file mode 100644
index 00000000..64efc9e3
--- /dev/null
+++ b/client/src/components/Settings/Dns/Cache/Form.js
@@ -0,0 +1,95 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import { Field, reduxForm } from 'redux-form';
+import { Trans, useTranslation } from 'react-i18next';
+import { shallowEqual, useSelector } from 'react-redux';
+import { renderInputField, toNumber } from '../../../../helpers/form';
+import { validateBiggerOrEqualZeroValue, getMaxValueValidator, validateRequiredValue } from '../../../../helpers/validators';
+import { FORM_NAME, SECONDS_IN_HOUR } from '../../../../helpers/constants';
+
+const validateMaxValue3600 = getMaxValueValidator(SECONDS_IN_HOUR);
+
+const getInputFields = ({ validateRequiredValue, validateMaxValue3600 }) => [{
+    name: 'cache_size',
+    title: 'cache_size',
+    description: 'cache_size_desc',
+    placeholder: 'enter_cache_size',
+    validate: validateRequiredValue,
+},
+{
+    name: 'cache_ttl_min',
+    title: 'cache_ttl_min_override',
+    description: 'cache_ttl_min_override_desc',
+    placeholder: 'enter_cache_ttl_min_override',
+    max: SECONDS_IN_HOUR,
+    validate: validateMaxValue3600,
+},
+{
+    name: 'cache_ttl_max',
+    title: 'cache_ttl_max_override',
+    description: 'cache_ttl_max_override_desc',
+    placeholder: 'enter_cache_ttl_max_override',
+}];
+
+const Form = ({
+    handleSubmit, submitting, invalid,
+}) => {
+    const { t } = useTranslation();
+
+    const { processingSetConfig } = useSelector((state) => state.dnsConfig, shallowEqual);
+    const {
+        cache_ttl_max, cache_ttl_min,
+    } = useSelector((state) => state.form[FORM_NAME.CACHE].values, shallowEqual);
+
+    const minExceedsMax = cache_ttl_min > cache_ttl_max;
+
+    const INPUTS_FIELDS = getInputFields({
+        validateRequiredValue,
+        validateMaxValue3600,
+    });
+
+    return <form onSubmit={handleSubmit}>
+        <div className="row">
+            {INPUTS_FIELDS.map(({
+                name, title, description, placeholder, validate, max,
+            }) => <div className="col-12" key={name}>
+                <div className="col-7 p-0">
+                    <div className="form__group form__group--settings">
+                        <label htmlFor={name}
+                               className="form__label form__label--with-desc">{t(title)}</label>
+                        <div className="form__desc form__desc--top">{t(description)}</div>
+                        <Field
+                            name={name}
+                            type="number"
+                            component={renderInputField}
+                            placeholder={t(placeholder)}
+                            disabled={processingSetConfig}
+                            normalize={toNumber}
+                            className="form-control"
+                            validate={[validateBiggerOrEqualZeroValue].concat(validate || [])}
+                            min={0}
+                            max={max}
+                        />
+                    </div>
+                </div>
+            </div>)}
+            {minExceedsMax
+            && <span className="text-danger pl-3 pb-3">{t('min_exceeds_max_value')}</span>}
+        </div>
+        <button
+            type="submit"
+            className="btn btn-success btn-standard btn-large"
+            disabled={submitting || invalid || processingSetConfig || minExceedsMax}
+        >
+            <Trans>save_btn</Trans>
+        </button>
+    </form>;
+};
+
+Form.propTypes = {
+    handleSubmit: PropTypes.func.isRequired,
+    submitting: PropTypes.bool.isRequired,
+    invalid: PropTypes.bool.isRequired,
+};
+
+export default reduxForm({ form: FORM_NAME.CACHE })(Form);
diff --git a/client/src/components/Settings/Dns/Cache/index.js b/client/src/components/Settings/Dns/Cache/index.js
new file mode 100644
index 00000000..22b8b7b6
--- /dev/null
+++ b/client/src/components/Settings/Dns/Cache/index.js
@@ -0,0 +1,42 @@
+import React from 'react';
+import { useTranslation } from 'react-i18next';
+import { shallowEqual, useDispatch, useSelector } from 'react-redux';
+import Card from '../../../ui/Card';
+import Form from './Form';
+import { setDnsConfig } from '../../../../actions/dnsConfig';
+import { selectCompletedFields } from '../../../../helpers/helpers';
+
+const CacheConfig = () => {
+    const { t } = useTranslation();
+    const dispatch = useDispatch();
+    const {
+        cache_size, cache_ttl_max, cache_ttl_min,
+    } = useSelector((state) => state.dnsConfig, shallowEqual);
+
+    const handleFormSubmit = (values) => {
+        const completedFields = selectCompletedFields(values);
+        dispatch(setDnsConfig(completedFields));
+    };
+
+    return (
+        <Card
+            title={t('dns_cache_config')}
+            subtitle={t('dns_cache_config_desc')}
+            bodyType="card-body box-body--settings"
+            id="dns-config"
+        >
+            <div className="form">
+                <Form
+                    initialValues={{
+                        cache_size,
+                        cache_ttl_max,
+                        cache_ttl_min,
+                    }}
+                    onSubmit={handleFormSubmit}
+                />
+            </div>
+        </Card>
+    );
+};
+
+export default CacheConfig;
diff --git a/client/src/components/Settings/Dns/Config/Form.js b/client/src/components/Settings/Dns/Config/Form.js
index a137130e..08514bc8 100644
--- a/client/src/components/Settings/Dns/Config/Form.js
+++ b/client/src/components/Settings/Dns/Config/Form.js
@@ -4,17 +4,18 @@ import { connect } from 'react-redux';
 import { Field, reduxForm, formValueSelector } from 'redux-form';
 import { Trans, withTranslation } from 'react-i18next';
 import flow from 'lodash/flow';
-
 import {
     renderInputField,
     renderRadioField,
     renderSelectField,
-    required,
-    ipv4,
-    ipv6,
-    biggerOrEqualZero,
     toNumber,
 } from '../../../../helpers/form';
+import {
+    validateBiggerOrEqualZeroValue,
+    validateIpv4,
+    validateIpv6,
+    validateRequiredValue,
+} from '../../../../helpers/validators';
 import { BLOCKING_MODES, FORM_NAME } from '../../../../helpers/constants';
 
 const checkboxes = [{
@@ -36,12 +37,12 @@ const checkboxes = [{
 const customIps = [{
     description: 'blocking_ipv4_desc',
     name: 'blocking_ipv4',
-    validateIp: ipv4,
+    validateIp: validateIpv4,
 },
 {
     description: 'blocking_ipv6_desc',
     name: 'blocking_ipv6',
-    validateIp: ipv6,
+    validateIp: validateIpv6,
 }];
 
 const getFields = (processing, t) => Object.values(BLOCKING_MODES)
@@ -77,7 +78,7 @@ let Form = ({
                     className="form-control"
                     placeholder={t('form_enter_rate_limit')}
                     normalize={toNumber}
-                    validate={[required, biggerOrEqualZero]}
+                    validate={[validateRequiredValue, validateBiggerOrEqualZeroValue]}
                 />
             </div>
         </div>
@@ -130,7 +131,7 @@ let Form = ({
                             component={renderInputField}
                             className="form-control"
                             placeholder={t('form_enter_ip')}
-                            validate={[validateIp, required]}
+                            validate={[validateIp, validateRequiredValue]}
                         />
                     </div>
                 </div>)}
diff --git a/client/src/components/Settings/Dns/index.js b/client/src/components/Settings/Dns/index.js
index 5ed8f9ca..41993f89 100644
--- a/client/src/components/Settings/Dns/index.js
+++ b/client/src/components/Settings/Dns/index.js
@@ -7,9 +7,10 @@ import Access from './Access';
 import Config from './Config';
 import PageTitle from '../../ui/PageTitle';
 import Loading from '../../ui/Loading';
+import CacheConfig from './Cache';
 
 const Dns = (props) => {
-    const [t] = useTranslation();
+    const { t } = useTranslation();
 
     useEffect(() => {
         props.getAccessList();
@@ -40,6 +41,10 @@ const Dns = (props) => {
                         dnsConfig={dnsConfig}
                         setDnsConfig={setDnsConfig}
                     />
+                    <CacheConfig
+                        dnsConfig={dnsConfig}
+                        setDnsConfig={setDnsConfig}
+                    />
                     <Access access={access} setAccessList={setAccessList} />
                 </>}
         </>
diff --git a/client/src/components/Settings/Encryption/Form.js b/client/src/components/Settings/Encryption/Form.js
index 69186b0b..a7bb3eec 100644
--- a/client/src/components/Settings/Encryption/Form.js
+++ b/client/src/components/Settings/Encryption/Form.js
@@ -10,10 +10,8 @@ import {
     renderSelectField,
     renderRadioField,
     toNumber,
-    port,
-    portTLS,
-    isSafePort,
 } from '../../../helpers/form';
+import { validateIsSafePort, validatePort, validatePortTLS } from '../../../helpers/validators';
 import i18n from '../../../i18n';
 import KeyStatus from './KeyStatus';
 import CertificateStatus from './CertificateStatus';
@@ -46,7 +44,8 @@ const clearFields = (change, setTlsConfig, t) => {
     };
     // eslint-disable-next-line no-alert
     if (window.confirm(t('encryption_reset'))) {
-        Object.keys(fields).forEach((field) => change(field, fields[field]));
+        Object.keys(fields)
+            .forEach((field) => change(field, fields[field]));
         setTlsConfig(fields);
     }
 };
@@ -158,7 +157,7 @@ let Form = (props) => {
                             type="number"
                             className="form-control"
                             placeholder={t('encryption_https')}
-                            validate={[port, isSafePort]}
+                            validate={[validatePort, validateIsSafePort]}
                             normalize={toNumber}
                             onChange={handleChange}
                             disabled={!isEnabled}
@@ -180,7 +179,7 @@ let Form = (props) => {
                             type="number"
                             className="form-control"
                             placeholder={t('encryption_dot')}
-                            validate={[portTLS]}
+                            validate={[validatePortTLS]}
                             normalize={toNumber}
                             onChange={handleChange}
                             disabled={!isEnabled}
diff --git a/client/src/helpers/constants.js b/client/src/helpers/constants.js
index a58d7529..6869a6cb 100644
--- a/client/src/helpers/constants.js
+++ b/client/src/helpers/constants.js
@@ -501,6 +501,9 @@ export const FORM_NAME = {
     STATS_CONFIG: 'statsConfig',
     INSTALL: 'install',
     LOGIN: 'login',
+    CACHE: 'cache',
 };
 
 export const smallScreenSize = 767;
+
+export const SECONDS_IN_HOUR = 60 * 60;
diff --git a/client/src/helpers/form.js b/client/src/helpers/form.js
index 73a79f4a..51cd4c1b 100644
--- a/client/src/helpers/form.js
+++ b/client/src/helpers/form.js
@@ -1,16 +1,12 @@
 import React, { Fragment } from 'react';
-import { Trans } from 'react-i18next';
 import PropTypes from 'prop-types';
-import {
-    R_IPV4, R_MAC, R_HOST, R_IPV6, R_CIDR, R_CIDR_IPV6,
-    UNSAFE_PORTS, R_URL_REQUIRES_PROTOCOL, R_WIN_ABSOLUTE_PATH, R_UNIX_ABSOLUTE_PATH,
-} from './constants';
 import { createOnBlurHandler } from './helpers';
+import { R_UNIX_ABSOLUTE_PATH, R_WIN_ABSOLUTE_PATH } from './constants';
 
 export const renderField = (props, elementType) => {
     const {
         input, id, className, placeholder, type, disabled, normalizeOnBlur,
-        autoComplete, meta: { touched, error },
+        autoComplete, meta: { touched, error }, min, max, step,
     } = props;
 
     const onBlur = (event) => createOnBlurHandler(event, input, normalizeOnBlur);
@@ -23,14 +19,17 @@ export const renderField = (props, elementType) => {
         autoComplete,
         disabled,
         type,
+        min,
+        max,
+        step,
         onBlur,
     });
     return (
-        <Fragment>
+        <>
             {element}
             {!disabled && touched && error
             && <span className="form__message form__message--error">{error}</span>}
-        </Fragment>
+        </>
     );
 };
 
@@ -43,6 +42,9 @@ renderField.propTypes = {
     disabled: PropTypes.bool,
     autoComplete: PropTypes.bool,
     normalizeOnBlur: PropTypes.func,
+    min: PropTypes.number,
+    max: PropTypes.number,
+    step: PropTypes.number,
     meta: PropTypes.shape({
         touched: PropTypes.bool,
         error: PropTypes.object,
@@ -227,136 +229,15 @@ renderServiceField.propTypes = {
     }).isRequired,
 };
 
-// Validation functions
-// If the value is valid, the validation function should return undefined.
-// https://redux-form.com/6.6.3/examples/fieldlevelvalidation/
-export const required = (value) => {
-    const formattedValue = typeof value === 'string' ? value.trim() : value;
-    if (formattedValue || formattedValue === 0 || formattedValue?.length !== 0) {
-        return undefined;
-    }
-    return <Trans>form_error_required</Trans>;
-};
-
-export const ipv4 = (value) => {
-    if (value && !R_IPV4.test(value)) {
-        return <Trans>form_error_ip4_format</Trans>;
-    }
-    return undefined;
-};
-
-export const clientId = (value) => {
-    if (!value) {
-        return undefined;
-    }
-    const formattedValue = value ? value.trim() : value;
-    if (formattedValue && !(
-        R_IPV4.test(formattedValue)
-        || R_IPV6.test(formattedValue)
-        || R_MAC.test(formattedValue)
-        || R_CIDR.test(formattedValue)
-        || R_CIDR_IPV6.test(formattedValue)
-    )) {
-        return <Trans>form_error_client_id_format</Trans>;
-    }
-    return undefined;
-};
-
-export const ipv6 = (value) => {
-    if (value && !R_IPV6.test(value)) {
-        return <Trans>form_error_ip6_format</Trans>;
-    }
-    return undefined;
-};
-
-export const ip = (value) => {
-    if (value && !R_IPV4.test(value) && !R_IPV6.test(value)) {
-        return <Trans>form_error_ip_format</Trans>;
-    }
-    return undefined;
-};
-
-export const mac = (value) => {
-    if (value && !R_MAC.test(value)) {
-        return <Trans>form_error_mac_format</Trans>;
-    }
-    return undefined;
-};
-
-export const isPositive = (value) => {
-    if ((value || value === 0) && value <= 0) {
-        return <Trans>form_error_positive</Trans>;
-    }
-    return undefined;
-};
-
-export const biggerOrEqualZero = (value) => {
-    if (value < 0) {
-        return <Trans>form_error_negative</Trans>;
-    }
-    return false;
-};
-
-export const port = (value) => {
-    if ((value || value === 0) && (value < 80 || value > 65535)) {
-        return <Trans>form_error_port_range</Trans>;
-    }
-    return undefined;
-};
-
-export const validInstallPort = (value) => {
-    if (value < 1 || value > 65535) {
-        return <Trans>form_error_port</Trans>;
-    }
-    return undefined;
-};
-
-export const portTLS = (value) => {
-    if (value === 0) {
-        return undefined;
-    }
-    if (value && (value < 80 || value > 65535)) {
-        return <Trans>form_error_port_range</Trans>;
-    }
-    return undefined;
-};
-
-export const isSafePort = (value) => {
-    if (UNSAFE_PORTS.includes(value)) {
-        return <Trans>form_error_port_unsafe</Trans>;
-    }
-    return undefined;
-};
-
-export const domain = (value) => {
-    if (value && !R_HOST.test(value)) {
-        return <Trans>form_error_domain_format</Trans>;
-    }
-    return undefined;
-};
-
-export const answer = (value) => {
-    if (value && (!R_IPV4.test(value) && !R_IPV6.test(value) && !R_HOST.test(value))) {
-        return <Trans>form_error_answer_format</Trans>;
-    }
-    return undefined;
-};
-
-export const isValidUrl = (value) => {
-    if (value && !R_URL_REQUIRES_PROTOCOL.test(value)) {
-        return <Trans>form_error_url_format</Trans>;
-    }
-    return undefined;
-};
+/**
+ * @param value {string}
+ * @returns {*|number}
+ */
+export const toNumber = (value) => value && parseInt(value, 10);
 
+/**
+ * @param value {string}
+ * @returns {boolean}
+ */
 export const isValidAbsolutePath = (value) => R_WIN_ABSOLUTE_PATH.test(value)
     || R_UNIX_ABSOLUTE_PATH.test(value);
-
-export const isValidPath = (value) => {
-    if (value && !isValidAbsolutePath(value) && !R_URL_REQUIRES_PROTOCOL.test(value)) {
-        return <Trans>form_error_url_or_path_format</Trans>;
-    }
-    return undefined;
-};
-
-export const toNumber = (value) => value && parseInt(value, 10);
diff --git a/client/src/helpers/helpers.js b/client/src/helpers/helpers.js
index 26954bed..cc4d7219 100644
--- a/client/src/helpers/helpers.js
+++ b/client/src/helpers/helpers.js
@@ -595,3 +595,15 @@ export const formatElapsedMs = (elapsedMs, t) => {
 export const setHtmlLangAttr = (language) => {
     window.document.documentElement.lang = language;
 };
+
+/**
+ * @param values {object}
+ * @returns {object}
+ */
+export const selectCompletedFields = (values) => Object.entries(values)
+    .reduce((acc, [key, value]) => {
+        if (value || value === 0) {
+            acc[key] = value;
+        }
+        return acc;
+    }, {});
diff --git a/client/src/helpers/validators.js b/client/src/helpers/validators.js
new file mode 100644
index 00000000..947cc96f
--- /dev/null
+++ b/client/src/helpers/validators.js
@@ -0,0 +1,209 @@
+import { Trans } from 'react-i18next';
+import React from 'react';
+import i18next from 'i18next';
+import {
+    R_CIDR,
+    R_CIDR_IPV6,
+    R_HOST,
+    R_IPV4,
+    R_IPV6,
+    R_MAC,
+    R_URL_REQUIRES_PROTOCOL,
+    UNSAFE_PORTS,
+} from './constants';
+import { isValidAbsolutePath } from './form';
+
+
+// Validation functions
+// https://redux-form.com/8.3.0/examples/fieldlevelvalidation/
+// If the value is valid, the validation function should return undefined.
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateRequiredValue = (value) => {
+    const formattedValue = typeof value === 'string' ? value.trim() : value;
+    if (formattedValue || formattedValue === 0 || (formattedValue && formattedValue.length !== 0)) {
+        return undefined;
+    }
+    return <Trans>form_error_required</Trans>;
+};
+
+/**
+ * @param maximum {number}
+ * @returns {(value:number) => undefined|string}
+ */
+export const getMaxValueValidator = (maximum) => (value) => {
+    if (value && value > maximum) {
+        i18next.t('value_not_larger_than', { maximum });
+    }
+    return undefined;
+};
+
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateIpv4 = (value) => {
+    if (value && !R_IPV4.test(value)) {
+        return <Trans>form_error_ip4_format</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateClientId = (value) => {
+    if (!value) {
+        return undefined;
+    }
+    const formattedValue = value ? value.trim() : value;
+    if (formattedValue && !(
+        R_IPV4.test(formattedValue)
+        || R_IPV6.test(formattedValue)
+        || R_MAC.test(formattedValue)
+        || R_CIDR.test(formattedValue)
+        || R_CIDR_IPV6.test(formattedValue)
+    )) {
+        return <Trans>form_error_client_id_format</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateIpv6 = (value) => {
+    if (value && !R_IPV6.test(value)) {
+        return <Trans>form_error_ip6_format</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateIp = (value) => {
+    if (value && !R_IPV4.test(value) && !R_IPV6.test(value)) {
+        return <Trans>form_error_ip_format</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateMac = (value) => {
+    if (value && !R_MAC.test(value)) {
+        return <Trans>form_error_mac_format</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateIsPositiveValue = (value) => {
+    if ((value || value === 0) && value <= 0) {
+        return <Trans>form_error_positive</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {boolean|*}
+ */
+export const validateBiggerOrEqualZeroValue = (value) => {
+    if (value < 0) {
+        return <Trans>form_error_negative</Trans>;
+    }
+    return false;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validatePort = (value) => {
+    if ((value || value === 0) && (value < 80 || value > 65535)) {
+        return <Trans>form_error_port_range</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateInstallPort = (value) => {
+    if (value < 1 || value > 65535) {
+        return <Trans>form_error_port</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validatePortTLS = (value) => {
+    if (value === 0) {
+        return undefined;
+    }
+    if (value && (value < 80 || value > 65535)) {
+        return <Trans>form_error_port_range</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateIsSafePort = (value) => {
+    if (UNSAFE_PORTS.includes(value)) {
+        return <Trans>form_error_port_unsafe</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateDomain = (value) => {
+    if (value && !R_HOST.test(value)) {
+        return <Trans>form_error_domain_format</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validateAnswer = (value) => {
+    if (value && (!R_IPV4.test(value) && !R_IPV6.test(value) && !R_HOST.test(value))) {
+        return <Trans>form_error_answer_format</Trans>;
+    }
+    return undefined;
+};
+
+/**
+ * @param value {string}
+ * @returns {undefined|string}
+ */
+export const validatePath = (value) => {
+    if (value && !isValidAbsolutePath(value) && !R_URL_REQUIRES_PROTOCOL.test(value)) {
+        return <Trans>form_error_url_or_path_format</Trans>;
+    }
+    return undefined;
+};
diff --git a/client/src/install/Setup/Settings.js b/client/src/install/Setup/Settings.js
index f12c3344..a939af41 100644
--- a/client/src/install/Setup/Settings.js
+++ b/client/src/install/Setup/Settings.js
@@ -10,9 +10,8 @@ import AddressList from './AddressList';
 
 import { getInterfaceIp } from '../../helpers/helpers';
 import { ALL_INTERFACES_IP, FORM_NAME } from '../../helpers/constants';
-import {
-    renderInputField, required, validInstallPort, toNumber,
-} from '../../helpers/form';
+import { renderInputField, toNumber } from '../../helpers/form';
+import { validateRequiredValue, validateInstallPort } from '../../helpers/validators';
 
 const STATIC_STATUS = {
     ENABLED: 'yes',
@@ -212,7 +211,7 @@ class Settings extends Component {
                                     type="number"
                                     className="form-control"
                                     placeholder="80"
-                                    validate={[validInstallPort, required]}
+                                    validate={[validateInstallPort, validateRequiredValue]}
                                     normalize={toNumber}
                                     onChange={handleChange}
                                 />
@@ -282,7 +281,7 @@ class Settings extends Component {
                                     type="number"
                                     className="form-control"
                                     placeholder="80"
-                                    validate={[validInstallPort, required]}
+                                    validate={[validateInstallPort, validateRequiredValue]}
                                     normalize={toNumber}
                                     onChange={handleChange}
                                 />
diff --git a/client/src/login/Login/Form.js b/client/src/login/Login/Form.js
index 4d8cfdd3..ac2d244c 100644
--- a/client/src/login/Login/Form.js
+++ b/client/src/login/Login/Form.js
@@ -3,8 +3,8 @@ import PropTypes from 'prop-types';
 import { Field, reduxForm } from 'redux-form';
 import { Trans, withTranslation } from 'react-i18next';
 import flow from 'lodash/flow';
-
-import { renderInputField, required } from '../../helpers/form';
+import { renderInputField } from '../../helpers/form';
+import { validateRequiredValue } from '../../helpers/validators';
 import { FORM_NAME } from '../../helpers/constants';
 
 const Form = (props) => {
@@ -28,7 +28,7 @@ const Form = (props) => {
                         placeholder={t('username_placeholder')}
                         autoComplete="username"
                         disabled={processing}
-                        validate={[required]}
+                        validate={[validateRequiredValue]}
                     />
                 </div>
                 <div className="form__group form__group--settings">
@@ -44,7 +44,7 @@ const Form = (props) => {
                         placeholder={t('password_placeholder')}
                         autoComplete="current-password"
                         disabled={processing}
-                        validate={[required]}
+                        validate={[validateRequiredValue]}
                     />
                 </div>
                 <div className="form-footer">