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Re: Filtering Source Addresses on gw-internet

  • From: Greg Ketell
  • Date: Tue Aug 12 16:52:42 1997

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At 03:05 PM 8/12/97 -0400, C. Jon Larsen wrote:
>gw-internet#show access-lists 120
>Extended IP access list 120
>    deny   ip any 10.0.0.0 0.255.255.255 log
>    deny   ip any 172.16.0.0 0.0.255.255 log
>    deny   ip any 172.17.0.0 0.0.255.255 log
>    deny   ip any 192.168.0.0 0.0.255.255 log
>    permit ip a.b.c.0 0.0.0.255 any (27429 matches)
>    deny   ip any any log

Line 2 and 3 could be replaced by
deny ip any 172.16.0.0 0.15.255.255 log

which would block all 172.16.0.0-172.31.0.0 as per the RFC.

You might also want to block 127.0.0.0.

GK

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