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PCs behind the ASA 5505 can not ping an internet address, help

There must be an ACL configuration issue.  How do I configure the ASA 5505 so that the computers

behind it can ping an internet IP address such 4.2.2.2 or www.google.com.

Thank you,

David

1 ACCEPTED SOLUTION

Accepted Solutions
Bronze

Re: PCs behind the ASA 5505 can not ping an internet address, he

If you don't have any ACL on the outside interface, please use the following command to allow ICMP through the ASA.

fixup protocol icmp.


Then try and ping. Let me know if that helps.

Also, please provide us a little more detail so that we can understand and help you better

Cheers,

Nash.

4 REPLIES
New Member

Re: PCs behind the ASA 5505 can not ping an internet address, he

First thing could be a NAT issue.

Are the IPs being used private IPs?

If so is NAT enabled?

Bronze

Re: PCs behind the ASA 5505 can not ping an internet address, he

If you don't have any ACL on the outside interface, please use the following command to allow ICMP through the ASA.

fixup protocol icmp.


Then try and ping. Let me know if that helps.

Also, please provide us a little more detail so that we can understand and help you better

Cheers,

Nash.

New Member

Re: PCs behind the ASA 5505 can not ping an internet address, he

Nash,

It's definitely a very powerful command.  works immediately!!

What does it fix?  ("fixup")

Thanks,

David

Bronze

Re: PCs behind the ASA 5505 can not ping an internet address, he

Hi David,


Fixup commands actually translate as inspect commands in MPF.

So fixup protocol icmp in effect adds an inspect icmp in the service policy on your ASA.

It inspects all outgoing ICMP traffic and creates a connection entry for every outgoing icmp echo-request, allowing icmp echo-replies to come back in.

That is how you get pings working through the ASA.


Ping is a combination of an ICMP echo request and ICMP echo reply.

Cheers,

Nash.

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