4 ms·

We used a vendor to put up two MPLS drops to every office. different providers, different routes from the building, etc. Turns out, further up the chain, an IS

We used a vendor to put up two MPLS drops to every office. different providers, different routes from the building, etc. Turns out, further up the chain, an ISP was buying transit from another ISP, and they all went on the same shared fiber that a nice backhoe operator found for us, about 800 miles away.

jrwr 8y ago
Trace route can help with that somewhat, I've noticed that a few times with redundant connections
- kortilla 8y ago
  The problem with traceroute is that it won’t show that two different ISPs are leasing strands out of the same bundle. All of the unexpected shared infra issues I’ve observed have been down at this lower level that never shows up at the IP layer.
  - nickpsecurity 8y ago
    Is there a directory or service one can use to get that information?
    - chucky_z 8y ago
      In my experience this exists for ISPs, but it's not easily available. I've used ISP brokers in the past and they've had this information in some proprietary systems when I've asked for quotes and proposals.
      - walrus 8y ago
        My experience corroborates this. I worked at two small ISPs, each with a fiber network spanning a few US states. They had their own databases to track this information, but as far as I know there was no central database. One of them used OSPInsight backed by a self-hosted SQL Server database. I don't know what the other place used.
foobiekr 8y ago
This is very common because of the way transport is built and sold. Doing real traffic engineering where shared risk link groups do not exist for the active and standby links is a lot of work and, moreover, is hard to keep working as operators change their networks (for maintenance, for other reasons). On top of the basic difficulty, there are other issues - layering makes this opaque, the service providers have become completely de-skilled, the business model for MPLS is getting killed by Over-The-Top providers who pretend they can give you equivalent service using multiple links and IPSEC tunnels. And so on.

jrwr 8y ago

Trace route can help with that somewhat, I've noticed that a few times with redundant connections

kortilla 8y ago
The problem with traceroute is that it won’t show that two different ISPs are leasing strands out of the same bundle. All of the unexpected shared infra issues I’ve observed have been down at this lower level that never shows up at the IP layer.
- nickpsecurity 8y ago
  Is there a directory or service one can use to get that information?
  - chucky_z 8y ago
    In my experience this exists for ISPs, but it's not easily available. I've used ISP brokers in the past and they've had this information in some proprietary systems when I've asked for quotes and proposals.
    - walrus 8y ago
      My experience corroborates this. I worked at two small ISPs, each with a fiber network spanning a few US states. They had their own databases to track this information, but as far as I know there was no central database. One of them used OSPInsight backed by a self-hosted SQL Server database. I don't know what the other place used.

foobiekr 8y ago

This is very common because of the way transport is built and sold. Doing real traffic engineering where shared risk link groups do not exist for the active and standby links is a lot of work and, moreover, is hard to keep working as operators change their networks (for maintenance, for other reasons). On top of the basic difficulty, there are other issues - layering makes this opaque, the service providers have become completely de-skilled, the business model for MPLS is getting killed by Over-The-Top providers who pretend they can give you equivalent service using multiple links and IPSEC tunnels. And so on.