Router for Metro Ethernet

Dylan Ebner dylan.ebner at
Mon Apr 12 12:55:29 CDT 2010

We use metro E for our WAN and our internet access delivery. The 2600 series routers do not have enough horsepower to do a 40 Mb connection and eigrp. The 2811 can do 40 mb and eigrp but they start to have difficulty when you add in inspection or large ACLs. We just last week turned a 40mb metroe circuit into a 60mb and the router, a 2811, is now have constant problems. We are replacing it with a 2921. However, this router also has 2 100mb connections from local lans that it is also terminiating. For our 100mb metro e connections we use 3845s. The 100 mb service terminates into NM-GEs, which have a faster throughput than the hwics. This setup works well. 
On our internet edges we use 2811s with their memory maxed. We have partial BGP routers from 2 isps. One connection is a 30mb and the other is a 25mb. no inspection is done on these but we do have stateless acls running on the inbound. these are running just fine today, but they sit at about 20% cpu  all the time.
When doing a metro e connection, make sure the router/switch can do traffic shaping. If it can't, you are relying on the provider to shape your outgoing traffic, which of course will happen down the line, adding additional delay during high usage times.

You should also look at the new cisco small metro switches. They can traffic shape, do bgp and have more than one interface. one of the annoying thing about metro e(at least with qwest) is  they have a tendancy to install new pe switches at your locations when you upgrade your service. this means a new connection from them and unless you have extra fiber or copper ports on your router. So to transition to the new circuit, you need to unplug your existing service first. And that means downtime, which no one likes.



-----Original Message-----
From: Jeffrey Negro [mailto:jnegro at] 
Sent: Monday, April 12, 2010 12:29 PM
To: nanog at
Subject: Router for Metro Ethernet

Before I get taken for a ride by salespeople, I figured it would be best to
ask the experts of Nanog....

My company is currently in talks to bring an ethernet circuit into our
headquarters, initially committing around 40Mbps.  The ISP will be providing
ethernet handoff, but I do not want their managed router offering (Adtran
4430) since it is pricey, non-redundant and I'd rather manage it myself.  My
question is about hardware.  Can I assume that I can use something like a
Cisco 2000 series router with two built in fast/gig ethernet ports, without
a WIC?  and since both sides are ethernet would the routing throughput be
near fast ethernet speed?  This is my first dealing with metro ethernet
offerings, and I don't want to assume that the Cisco throughput rates listed
for T1/ADSL etc. are the same for a metro ethernet as the WAN.

Any and all suggestions on the hardware would be greatly appreciated.  Thank
you in advance!

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