@Override
	public String getHostByAddr(byte[] ip) throws UnknownHostException {
		try {
			String addr = DnsUtils.numericToTextFormat(ip);
			Record[] records = new Lookup(addr, Type.PTR).run();
			if (records == null) {
				throw new UnknownHostException(addr);
			}
			PTRRecord ptr = (PTRRecord) records[0];
			return ptr.getTarget().toString();
		} catch (TextParseException e) {
			throw new UnknownHostException(e.getMessage());
		}
	}
Finds PTR records (reverse dns lookups) for the ip address.

@param ip ip address to lookup.
@return The host name found for the ip address.
@throws UnknownHostException occurs when id is not available in DNS
ngrinder-runtime/src/main/java/org/ngrinder/dns/LocalManagedDnsImpl.java