All carrier Ethernet services are tunnels provided by VPLS Psuedowire or VXLAN services. Did you really expect a VLAN to be layer 2 switched everywhere?
Ryan On Oct 14 2020, at 11:03 am, Rod Beck <[email protected]> wrote: > > I always heard this service was really Layer 3 disguised as Layer 2. > > > From: NANOG <[email protected]> on > behalf of Ryan Hamel <[email protected]> > Sent: Wednesday, October 14, 2020 7:54 PM > To: Mike Hammett <[email protected]> > Cc: [email protected] <[email protected]> > Subject: Re: Cogent Layer 2 > > > Mike, > > Layer 2 is fine once it works. > You will have to put up with whatever VLAN tags they pick, if you plan on > having multiple virtual circuits on a 10G hub. > They do like to see into the flows of traffic, as they only allow up to > 2Gbits/flow, per there legacy infrastructure. > > If the circuit doesn't work on turn up (which is more than likely), you'll > have to be abrasive with their NOC and demand escalations. > > > IMO, if it's 1Gbit or less per circuit and can deal with ^, you're fine, > otherwise look for another carrier. > > ----- > Below is what I got from Cogent about their layer 2: > We offer Ethernet over MPLS transport utilizing Cisco FAT Pseudowire (Flow > Aware Transport). Our service is a fully protected service, so if we suffer a > fiber cut or other disruption along the primary path, our IS-IS IP > fast-reroute enabled MPLS backbone will swing all traffic over to another > pre-determined path across our backbone with usually no packet loss or > disruption in service. > In order for our service to work correctly and provide the automatic > redundancy, we need to verify that the traffic traversing the network can be > hashed correctly by our routers. For this to happen, Cogent has to see the > src-dst IP address or if you are running MPLS over the circuit, we need to > see your MPLS labels. The hashing works by placing each flow of data on a > separate 10GE or 100GE interface between the routers, so that traffic is > evenly dispersed across all available capacity along the path. A flow is > defined as a src-dst IP pair or a customer MPLS label, so the more IP pairs > or MPLS labels, the better the traffic load-balances. Cogent has decided to > impose a 2Gbps/flow restriction for our own traffic engineering purposes, > which aim to make sure that no single customer can overrun a 10GE interface > anywhere on our network (since we do not sell 10GE Wave services). > The reason we have the limitation in place is for our own traffic engineering > purposes, which aims to make sure that no single customer can overrun a 10GE > interface anywhere on our network (since we do not sell 10GE Wave services). > Since most uplinks between routers are Nx10GE or Nx100GE, we want to make > sure that all customer traffic can be load-balanced across the uplink > capacity evenly, which makes it easier to reroute traffic in the event of a > fiber cut or other disruption. One would think that with 100GE interfaces, it > would not be possible to overrun the interface if we allowed full > 10Gbps/flow, however most 100GE interfaces, at the chip level are broken down > into 10Gbps lanes and the interfaces do not have a way to easily determine > that a lane through the interface is at capacity, so as new flows enter the > interface, they could get allocated to a lane that is already full and > therefore experience packet loss. > So that we can complete our technical review for this request, need the > following questions answered: > 1 - What equipment will be directly connected to Cogent interface? > 2 - How are the servers/equipment behind the edge device connected, GE or > 10GE interfaces? > 3 - Will you be doing any type of tunneling or load-balancing that would hide > the src-dst IP addresses or MPLS labels of the servers/equipment? > 4 - Will any single data flow (src-dst IP pair or MPLS label) be more than > 2Gbps? > 5 – What is the purpose of the connection? (Internet traffic backhaul, data > center connectivity, replication, extending point-of-presence, etc..) > 6 – Will you be running MACSec over our L2 service? > 7 – Will you need to pass multiple VLANs and/or Jumbo frames? > ---------- > Ryan > On Oct 14 2020, at 10:36 am, Mike Hammett <[email protected]> wrote: > > Are any legitimate beefs with Cogent limited to their IP policies, BGP > > session charges, and peering disputes? Meaning, would using them for layer > > 2 be reasonable? > > > > > > > > ----- > > Mike Hammett > > Intelligent Computing Solutions (http://www.ics-il.com/) > > > > > > > > > > > > > > > > > > > > Midwest Internet Exchange (http://www.midwest-ix.com/) > > > > > > > > > > > > > > > > The Brothers WISP (http://www.thebrotherswisp.com/) > > > > > > > > > > > > > > >
