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Re: commonly blocked ISP ports

  • From: Kim Onnel
  • Date: Thu Sep 15 03:30:49 2005
  • Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta;; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:references; b=ANLjVMb/tUN1u5EKMiFXRNLgsV3XLOxxIs840sHEjkTeASjbGrydbRNB2jcyjw62W49opAD5dBlU4HVtaYv1v7Dhu4PtAn6RxWGmKE5ypF73sghucNxh8KS53UUsq0WA7zBX9zT6+4KkaEqEWmJnHoBdMUSY323Bj7R88uy86gw=

Depends where you will put your ACL too,

we have this on our Ingress from the internet

    10 deny ip any (118 matches)
    20 deny ip any (23297 matches)
    30 deny ip any (8 matches)
    40 deny ip any (19 matches)
    50 deny tcp any any eq 135 (6750649 matches)
    60 deny udp any any eq 135 (20275 matches)
    70 deny tcp any any eq 445 (18420302 matches)
    80 deny udp any any eq 1026 (3481591 matches)
    90 deny ip x.x.x.x any

where x.x.x.x is your IPs

and you could add bogons

But of course you might not want to block some of those as some home customers could use them to connect back to their intranet, but those should use tunnels IMHO.

On 9/15/05, Peter Dambier <> wrote:

There is only one port worth blocking:

Block port 80 (http)

All other ports might be in use for redirected ssh, telnet, ftp, ...

Blocking port 80 will keep windows people from accidently clicking nonsense.


Kind regards,
Peter and Karin Dambier

Luke Parrish wrote:
> Everyone,
> Does anyone have a reference point for commonly blocked ports?
> We have a list, some reactive and some proactive, however we need to
> remove ports that are no longer a threat and add new ones as they are
> published.
> Thanks
> luke

Peter and Karin Dambier
Graeffstrasse 14
D-64646 Heppenheim
+49-6252-671788 (Telekom)
+49-179-108-3978 (O2 Genion)
+49-6252-750308 (VoIP:

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