How do I open a port on a Cisco 2801 router?

How do I open a port on a cisco 2801 router?  Or how do I tell if a port is open?

Thank you
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asuming you are using nat.
you need for example to recieve mail from outside ?  (port 25)

ip nat inside source static tcp <inside address server>  25 <interface outside> 25

and ad this to access-list
access-list XXX permit tcp any any eq smtp   or
access-list XXX permit tcp any (outside ip) eq smtp
remember to replace the whole access-list XXX

if you want to see if the port is open from the outside ( internet ) and use shields up !

If this is not what you mean post your config and explane more

If you don't have any access lists on any of your interfaces then the router is wide open.
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cas_threeAuthor Commented:
I do have access lists, all I need to know is if SNMP is enabled.
You want to allow snmp through the router or you want to know if it is enabled on the router ?

If you want to allow it through I believe damalano answered your question.

cas_threeAuthor Commented:
I would lilke to know if it's enabled.
amprantiConnect With a Mentor Commented:
If ytou want to find if snmp is enable when you are in enable mode:

sh run | i snmp

If you find any community names or traps snmp is enable
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