nanog mailing list archives

Re: "Defensive" BGP hijacking?


From: Sandra Murphy <sandy () tislabs com>
Date: Wed, 14 Sep 2016 17:49:55 -0400


On Sep 13, 2016, at 8:08 PM, Ca By <cb.list6 () gmail com> wrote:

On Tuesday, September 13, 2016, Doug Montgomery <dougm.work () gmail com>
wrote:

If only there were a global system, with consistent and verifiable security
properties, to permit address holders to declare the set of AS's authorized
to announce their prefixes, and routers anywhere on the Internet to
independently verify the corresponding validity of received announcements.

*cough      https://www.nanog.org/meetings/abstract?id=2846     cough*

I now return us to our discussion of network police, questionnaires for
network security, and the use of beer as a motivating force.

dougm


Interesting that backconnect has invalid ROA issued

http://bgp.he.net/AS203959#_prefixes

Well, no, that’s not what the bgp.he.net (live long and prosper!) icons mean.

There is nothing invalid about the ROA.  And BackConnect did not issue it.

The red key means that AS203959 BackConnect Security LLC is announcing routes for 181.215.239.0/24, 191.96.128.0/24. 
etc that are invalid according to the RPKI.  Someone else with the right to use 181.215.239.0/24, 191.96.128.0/24. etc, 
created ROAs authorizing some other AS(s) to originate the route.

You can look at the ROAs for those prefixes with red keys in http://rpki-browser.realmv6.org (and with the RPKIviz and 
EOM tools from www.securerouting.net).  You can see that there are ROAs for 181.214.0.0/15 for AS50673, AS60458, 
AS61440.  and ROAs for 191.96.0.0/16 for AS61440, AS60458, AS29073, AS33182, AS37692.  and ROAs for 191.101.0.0/16 for 
AS60458, AS37692, AS61440.

Except.

It looks like, maybe, BackConnect was re-allocated the four prefixes with red keys, and whoever reallocated the 
prefixes to them created ROAs for their aggregate — but not for their customers.  See for example 
http://bgp.he.net/net/191.96.128.0/24 (and http://bgp.he.net/net/191.101.191.0/24)

This can occurred as the world backfills the existing allocations and the customers don’t keep up and their providers 
aren’t careful.  Some RPKI implementations will warn you that the ROA you are about to create will make existing routes 
appear invalid to the RPKI.

Just for fun, take a look at the IRR entries for the four prefixes with red key icons:

route:      191.96.128.0/24
descr:      Clan Servers
origin:     AS20473
notify:     net-support () ap equinix com
notify:     noc () ap equinix com
mnt-by:     MAINT-EQUINIXPAC
changed:    mvillalobos () ap equinix com 20151229
source:     NTTCOM

route:      191.96.129.0/24
descr:      Clan Servers
origin:     AS20473
notify:     net-support () ap equinix com
notify:     noc () ap equinix com
mnt-by:     MAINT-EQUINIXPAC
changed:    mvillalobos () ap equinix com 20151229
source:     NTTCOM

route:      191.101.191.0/24
descr:      Clan Servers
origin:     AS20473
notify:     net-support () ap equinix com
notify:     ap-noc () ap equinix com
mnt-by:     MAINT-EQUINIXPAC
changed:    mporquez () ap equinix com 20151227
source:     NTTCOM

route:      181.215.239.0/24
descr:      Proxy route object registered by AS2764
origin:     AS45177
remarks:    This route object was created by AAPT on behalf of a customer.
remarks:    As some of AAPTs upstream networks filter based on IRR objects,
remarks:    this route object has been created to ensure that the advertisement
remarks:    of this prefix is not rejected.
notify:     routing.shared () aapt com au
mnt-by:     MAINT-AS2764
changed:    nobody () aapt com au 20160106
source:     RADB

(like the “nobody” part???)


At least the aggregate announcements aren’t proxies.

route:      181.214.0.0/19
descr:      Digital Energy Technologies LTD.
origin:     AS61440
mnt-by:     MAINT-AS61440
changed:    modestas () host1plus com 20140814  #13:04:53Z
source:     RADB

route:      191.101.0.0/21
descr:      Digital Energy Technologies LTD.
origin:     AS25761
mnt-by:     MAINT-AS61440
changed:    modestas () host1plus com 20150610  #08:53:38Z
source:     RADB

—Sandy

(Since bgp.he.net changes as the routing world changes, the red keys could be gone by the time anyone looks, of course.)




On Tue, Sep 13, 2016 at 2:51 PM, Mel Beckman <mel () beckman org <javascript:;>>
wrote:

Blake,

I concur that these are key questions. Probably _the_ key questions. The
fabric of the Internet is today based on trust, and BGP's integrity is
the
core of that trust.

I realize that BGP hijacking is not uncommon. However, this is the first
time I've seen in it used defensively. I don't see a way to ever bless
this
kind of defensive use without compromising that core trust. If Internet
reachability depends on individual providers believing that they are
justified in violating that trust when they are attacked, how can the
Internet stand?

In addition to the question posed to Bryant about whether he would take
this action again, I would like to add: what about the innocent parties
impacted by your actions? Or do you take the position there were no
innocent parties in the hijacked prefixes?

-mel via cell

On Sep 13, 2016, at 11:40 AM, Blake Hudson <blake () ispn net
<javascript:;>> wrote:



Bryant Townsend wrote on 9/13/2016 2:22 AM:
This was the point where I decided
I needed to go on the offensive to protect myself, my partner,
visiting
family, and my employees. The actions proved to be extremely
effective,
as
all forms of harassment and threats from the attackers immediately
stopped.


Bryant, what actions, exactly, did you take? This topic seems
intentionally glossed over while you spend a much larger amount of time
explaining the back story and your motivations rather than your actions.

Questions I was left with:

1. What prefixes have you announced without permission (not just this
 event)?
2. How did you identify these prefixes?
3. Did you attempt to contact the owner of these prefixes?
4. Did you attempt to contact the origin or transit AS of these
prefixes?
5. What was the process to get your upstream AS to accept these prefix
 announcements?
6. Was your upstream AS complicit in allowing you to announce prefixes
 you did not have authorization to announce?





--
DougM at Work


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