[sclug] Potential in-bound routing failure on BT: any thoughts welcomed

[Neil Brown]

On 7 Apr 2013, at 20:47, Keith Edmunds <kae at midnighthax.com> wrote:

Keith ? thank you.

>  I'm now with Andrews and Arnold

If BT cannot get this resolved, then a migration is imminent, and A&A is on the list of potentials.

> is it 100, or 10?

100 ? definitely not a non-routable IP.

> I suggest you ask BT if they are using CG-NAT.

Asked, and awaiting an answer, straight or otherwise... I feel I made some progress on my last call, as the agent did at least know what CG-NAT was, and promised to investigate to see if anything obvious has changed, but I am not holding my breath.

> 'whois' on the IP address you have (the 100 one)

Interesting... I hadn't thought of that. The answer is not what I was expecting, and I don't yet know what it might mean, although it might suggest something like CG-NAT:

NetRange:       100.64.0.0 - 100.127.255.255
CIDR:           100.64.0.0/10
OriginAS:       
NetName:        SHARED-ADDRESS-SPACE-RFCTBD-IANA-RESERVED
NetHandle:      NET-100-64-0-0-1
Parent:         NET-100-0-0-0-0
NetType:        IANA Special Use
Comment:        This block is used as Shared Address Space. Traffic from these addresses does not come from IANA. IANA has simply reserved these numbers in its database and does not use or operate them. We are not the source of activity you may see on logs or in e-mail records. Please refer to http://www.iana.org/abuse/
Comment:        
Comment:        Shared Address Space can only be used in Service Provider networks or on routing equipment that is able to do address translation across router interfaces when addresses are identical on two different interfaces.

> I would ping from another connection

Done, from two different networks ? total packet loss on each occasion.

> That may help.

I'm really grateful for your thoughts ? thank you.

> What may help much more is changing ISPs.

Noted, and, as above, whilst not something I'm keen to (as, frankly, BT has been fine for several years, whatever I have tried to do with my connection), I'm not ruling it out.


Best wishes,

Neil

__________

Neil Brown
neil at neilzone.co.uk | http://neilzone.co.uk