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View Full Version : to ianuk and others regarding cogent


Chrysalis
23-09-2005, 23:47
Ok a few turn of events here.

My contact was going to route me over manually or rather my /24 to a new route (not cogent) but it got blocked by his bosses. Everyone can probably guess why, for those who dont know much about cogent their transit is dirt cheap.

But in turn they have moved various routes of cogent and now the load is no longer congested. Of course cogent been the way they are they had some issue in usa today causing me new problems but at least it wasn't in the usual place.

I also did some other tests. Obviously unless NTL have a looking glass on their website I can only do these tests inbound.

Traceroute from a provider to ntlworld.com abovenet 150ms - best possible route
Traceroute from same provider to me nrs/xeex 190ms at point of entry to ntl's network - middle possible route.

cogent is the 3rd transit the provider has but they blocked cogent to uk for outbound.

1 - is ntlworld hosted inside the ntl network, traceoutes seem to indicate so.
2 - why is ntlworld using higher quality transit then my own connection, is it ntl forcing inbound routes as well as outbound on cheapest routes? or just some other bizarre reason. If ntl staff reply honesty please.

Ignition
23-09-2005, 23:55
Ok a few turn of events here.

My contact was going to route me over manually or rather my /24 to a new route (not cogent) but it got blocked by his bosses. Everyone can probably guess why, for those who dont know much about cogent their transit is dirt cheap.

But in turn they have moved various routes of cogent and now the load is no longer congested. Of course cogent been the way they are they had some issue in usa today causing me new problems but at least it wasn't in the usual place.

I also did some other tests. Obviously unless NTL have a looking glass on their website I can only do these tests inbound.

Traceroute from a provider to ntlworld.com abovenet 150ms - best possible route
Traceroute from same provider to me nrs/xeex 190ms at point of entry to ntl's network - middle possible route.

cogent is the 3rd transit the provider has but they blocked cogent to uk for outbound.

1 - is ntlworld hosted inside the ntl network, traceoutes seem to indicate so.
2 - why is ntlworld using higher quality transit then my own connection, is it ntl forcing inbound routes as well as outbound on cheapest routes? or just some other bizarre reason. If ntl staff reply honesty please.

1) Yes.
2) Just the way the routing protocol goes, there's nothing bizarre about it there are just multiple ways to get to destinations and BGP came up with those routes.

If you are going to be asking these questions you need to understand what you are talking about, it's basic routing that each router decides where the next hop is going to be and in this case wherever you were tracing from decides which path to take for the next hop.

I'm fairly sure that ntl have no control over this at all as they can only control traffic while inside their network and can't control which path your providers decide to send your packets.

Paul
23-09-2005, 23:58
ntlworld is on servers at Winnersh.

Chrysalis
24-09-2005, 00:24
yeah I am aware of how that works but routes can be manipulated and static routes can be used no isp can decide on the entire route but they can preference a particular isp been used in and out of their network.

eg. if bgp was really picking the routes without manipulation you would think it would pick the better route to myself and not only that pick the same route for me and ntlworld.com since we are on the same isp.

Whats interesting tho if i trace the ip before ntlworld.com it goes over the poorer route, and if i trace ntlworld.com it goes over abovenet again I can repeat this again and again. So what would make bgp pick a different route to the hop before the site?

IanUK
24-09-2005, 01:36
The last 2 nights Cogent has been ok here, I think it looks like the new fibre has gone live as promised by Cogent.

I'll give it a week or so to be sure, but it looks much better.
Steampowered.com and shacknews.com are also back on Poplar tonight !

hurrah !