Re: ACL "in" for filtering Telnet -- fixed & Thanks !

From: ccie lab (ccie_lab@xxxxxxxxxxx)
Date: Wed Jun 14 2000 - 23:35:44 GMT-3


   
Hi, first I would like to thank:
Dave Gingrich and Pamela Forsyth (CCIE #3439)
for their quick reply and helpful hint to solve the issue posted on
Monday.

Today, I spent an hour on that issue and found the solution.

First let clarify the issue to confuse no one any more.

R1:s1 --------- s0: R2 :s1 -------- s0: R3 (w/ EIGRP)

requirement:
  1. only allow R1 to Telnet R3 and block any IP services.
  2. use access-list (ACL) on R2 only and apply ACL with "IN " only.

My solution:
access-list 100 permit eigrp any any
access-list 100 permit TCP any eq TELNET any established
apply ACL 100 to R2:s1 as "IN"

access-list 101 permit eigrp any any
access-list 101 permit TCP any any eq TELNET
apply ACL 101 to R2:s0 as "IN"

That's it. I think that the trick is you have to allow reply of TCP
package to get through R2 by specifying the prot parameter of
Destination field (point to R1 -- the source of original telnet
package !

regards,

James Z

11:00 p.m.
Wed.
NYC



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