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how to drop packets


in my lan i see valid source IP addresses try to reach a invalid source IP addresses which is not available in the LAN.

for example in my firewall log

Deny inbound UDP from to on interface inside is valid but is invalid or non existent

can you help create a acces list or packet drop config in switch so that this packet does not reach the firewall                  

Everyone's tags (1)

how to drop packets


Use you own names interfaces etc, but something along these lines.

ip access-list extended YOURLIST
deny udp host eq 1042 host eq 161
permit ip any any
interface vlan 16
ip address
ip access-group YOURLIST in

By the way UDP port is used for SNMP.
Looks like your device is trying to contact an snmp server.

Useful links:-

Please rate useful posts.

Regards, Alex. Please rate useful posts.
Super Bronze

Re: how to drop packets


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BTW, an alternative to using an ACL, you might be able to route bad packets to a null interface, which also effectively drops them.