Team Cymru / Spamhaus

Mailman List Mirror (Read Only)
1

Hi all,

We're evaluating whether to add BGP feeds from these two sources in attempt
to minimize exposure to DoS.

The Team Cymru BOGON list (

http://www.team-cymru.org/Services/Bogons/bogon-bn-nonagg.txt or

http://www.team-cymru.org/Services/Bogons/bogon-bn-agg.txt

)

looks promising and common-sense.

We already filter RFC1918 inbound at our edge, and are interested to see if
adding the rest of the blocks will have a significant positive effect.

If it does, we're planning to try the IPv4 FULLBOGON list:

http://www.team-cymru.org/Services/Bogons/fullbogons-ipv4.txt

We're a little more leery about trying Spamhaus's BGPf service (DROP, EDROP
and BCL,

http://www.spamhaus.org/bgpf/

)

because we really want to avoid false positives.

Just wondering if anyone has any words of caution ("False positives! Avoid
FULLBOGONS and Spamhaus!"), or words of praise ("Do it all! These services
are wonderful!") before we take the plunge.

Thanks,

Adam

2

That wont stop a DoS.

A DoS or DDoS is pure bandwidth wars for the most part, if someone is to DoS you, they already have your IP's and urls they need to attack you, thus a spam list won't stop an attack.

If you want to minimize actual spam, sure.

3

Could I also encourage you to do anti-spoofing filtering, a la BCP38?

- - ferg

4

Appreciate the Clarification Darden, I wasn't aware Spamhaus had this other division / service, time for some reading.

5

We're evaluating whether to add BGP feeds from these two sources in attempt
to minimize exposure to DoS.

The Team Cymru BOGON list (

http://www.team-cymru.org/Services/Bogons/bogon-bn-nonagg.txt or

http://www.team-cymru.org/Services/Bogons/bogon-bn-agg.txt

These really won't do anything to stop DoS attacks. Common DDoS attack traffic these days comes via reflection from non-spoofed sources replying to a spoofed public IP target.

http://www.team-cymru.org/Services/Bogons/fullbogons-ipv4.txt

Same here. Whether or not its worth null routing unallocated IP space may be debatable, but again, it't not going to help protect you from a typical real DDoS.

We're a little more leery about trying Spamhaus's BGPf service (DROP, EDROP
and BCL,

BGPf - Spamhaus BGP feed - The Spamhaus Project

This is more about stopping spam from entering your network and stopping compromised hosts on your network from becoming active in botnets (by cutting off their command and control).

6

Not quite.

    DROP (Don't Route Or Peer) and EDROP are advisory "drop all traffic"
    lists, consisting of netblocks that are "hijacked" or leased by professional
    spam or cyber-crime operations (used for dissemination of malware,
    trojan downloaders, botnet controllers). The DROP and EDROP lists are
    a tiny subset of the SBL, designed for use by firewalls and routing
    equipment to filter out the malicious traffic from these netblocks.

(Source: http://www.spamhaus.org/drop/, linked from the URL quoted above)

-- Matthias

7

+1, blanket banning is probably not the best way to go.