topic ICMP Stateful in Network Security https://community.cisco.com/t5/network-security/icmp-stateful/m-p/1471267#M708954 <P>Hi,</P><P></P><P>Most of us knows that ICMP is not a stateful protocol, and we can make it using ICMP inspection in ASA.</P><P></P><P>As per my understanding,</P><P></P><P>In TCP, TCP Flags are making TCP capable of stateful protocol, In UDP, src and dst port numbers playing the role to make it stateful.. But what makes ICMP to become stateful!!!</P><P></P><P>Regards,</P><P></P><P>Manu B.</P> Mon, 11 Mar 2019 17:56:58 GMT manuadoor 2019-03-11T17:56:58Z ICMP Stateful https://community.cisco.com/t5/network-security/icmp-stateful/m-p/1471267#M708954 <P>Hi,</P><P></P><P>Most of us knows that ICMP is not a stateful protocol, and we can make it using ICMP inspection in ASA.</P><P></P><P>As per my understanding,</P><P></P><P>In TCP, TCP Flags are making TCP capable of stateful protocol, In UDP, src and dst port numbers playing the role to make it stateful.. But what makes ICMP to become stateful!!!</P><P></P><P>Regards,</P><P></P><P>Manu B.</P> Mon, 11 Mar 2019 17:56:58 GMT https://community.cisco.com/t5/network-security/icmp-stateful/m-p/1471267#M708954 manuadoor 2019-03-11T17:56:58Z Re: ICMP Stateful https://community.cisco.com/t5/network-security/icmp-stateful/m-p/1471268#M708955 <HTML><HEAD></HEAD><BODY><P>The ASA builds a ICMp connection for the icmp echoes that is sees. It creates a session based on the identification/sequence number of the icmp header, it's source and destination ip addresses and its type and code. So, it knows what the icmp reply for that packet will look like and it will allow the return traffic.</P><P></P><P>I hope it clarifies it.</P><P></P><P>PK</P></BODY></HTML> Wed, 09 Jun 2010 14:43:08 GMT https://community.cisco.com/t5/network-security/icmp-stateful/m-p/1471268#M708955 Panos Kampanakis 2010-06-09T14:43:08Z