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let isIpv4Valid = ipStr.match('/^((25[0-5]|2[0-4][0-9]|[10]?[0-9]?[0-9])(\.|$)){4}/ig')
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(\b25[0-5]|\b2[0-4][0-9]|\b[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}
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let isIpv4Valid = ipStr.match('/\b((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4}\b/ig')