nslookup does not give any result on those IP addresses. So not able to figure out who is causing this. Is there a way to check the reason, why they do not answer to the SYN-ACK's? Thanks and Regards Puneet ---------------------------------------- > Date: Thu, 6 Nov 2014 15:30:46 +0100 > From: me@xxxxxxxxxxx > To: puneet.agr@xxxxxxxxxxx > CC: kernelnewbies@xxxxxxxxxxxxxxxxx > Subject: Re: lots of connections in SYN_RECV state > > Hi > > Am 2014-11-06 14:27, schrieb Puneet Agarwal: >> I have a couple of servers, for the past few days I am seeing lots of >> connections in SYN_RECV state in netstat commands output. > > This *could* be the result of a SYN-flood attack on your server. > > >> Is there a solution to this problem? > > The Wikipedia page mentions some countermeasures (if it indeed is an > attack and not a networking stack issue). > > http://en.wikipedia.org/wiki/SYN_flood > > Maybe you could check from which IP addresses these SYNs come from and > investigate why they do not answer to the SYN-ACK request of your > server. > > > Cheers, > > Silvan _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
