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Strange activity ping wise

Brent Rockburn
Level 2
Level 2

I have an ASA that can't ping ip addresses that end with an even number. For instance I can ping 4.2.2.3 and 4.2.2.1 but can't ping 4.2.2.2 I've tried with different ip addresses but it's always the same result.

Any ideas?

6 Replies 6

Richard Burts
Hall of Fame
Hall of Fame

Brent

My first suggestion would be to check and see if there is a route statement for network 4 that has an odd mask which might result in sending requests for addresses with even numbers on a different (invalid) path.

My second suggestion is that somewhere along the path someone has configured an access list to filter traffic with an unusual mask which permist only odd values.

Further question: is this just in 4.2.2, or just in 4, or does it impact other networks as well?

HTH

Rick

HTH

Rick

Hey Rick,

Thanks for the quick response.

The 4 network is just a network on the internet it does the same with any address that ends in an even octet.

My outside IP address is 64.221.173.98 and the mask is 255.255.255.240 which was provided to us by our ISP.

Brent

So it has this behavior for any IP address in the Internet? Would you post the output of show route from the ASA?

HTH

Rick

HTH

Rick

US3432-asa# sh route

Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP

i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area

* - candidate default, U - per-user static route, o - ODR

P - periodic downloaded static route

Gateway of last resort is 64.221.173.97 to network 0.0.0.0

C 64.221.173.96 255.255.255.240 is directly connected, outside

C 127.1.0.0 255.255.0.0 is directly connected, _internal_loopback

C 10.3.37.0 255.255.255.0 is directly connected, inside

S* 0.0.0.0 0.0.0.0 [1/0] via 64.221.173.97, outside

here you go

Brent

The easy problem would have been some odd thing in the routing table. But your table seems quite normal. So it must be something else. I wonder if there could be some translation issue or some access policy. Perhaps the best thing would be to ask you is you could post the config (sanitized of sensitive info such as passwords).

HTH

Rick

HTH

Rick

I moved the vpn server entry in the config to .13 on our network and it works fine ... I think it's an issue with the providers upstream router which is not a cisco box. They're going to call me to do some troubleshooting and I'll post what happens here.

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