Question : icmp ,snmp

Hi,

Can any one explain me the ports numbers used for icmp both for echo request and reply

Any standard piece of code for blocking echo request and echo reply ;please help with the code for both router and pix;

Please help with the port for snmp also

thx

Answer : icmp ,snmp

Here is a good reference for ICMP type messages:

http://www.iana.org/assignments/icmp-parameters

To block ICMP echo and echo reply (inbound I assume):

Router:

access-list 150 deny icmp any any echo
access-list 150 deny icmp any any echo-reply
access-list 150 permit ip any any    <--add if you are allowing everything by default

int
ip access-group 150 in

PIX:

access-list outside_access_in extended deny icmp any any echo
access-list outside_access_in extended deny icmp any any echo-reply
access-group outside_access_in in interface outside


SNMP polling uses UDP 161
SNMP Traps use UDP 162