Question for our cisco experts

themagicone

So this isn't really cert based but I figured someone might be able to help me out. I'm working with a company to bring up a 100MB MPLS Link. At each site there is a Cisco ASR1002 and it is connected to the MPLS via a duplex fiber pair from Level 3. Our first issue was the fiber had a SC end and the router had a single LC fiber SFP. Got that problem solved, got the link to come up (up/up) but now I can't ping any other address on MPLS. It is a ptp connection, the SFP has an address of 192.168.100.2/30 and the other side is 100.1. I can't ping the 100.1 address even though I know it's up (or at least that is what I have been told). The engineer keeps wanting me to set the port (g0/0/0) to full duplex 100mb BUT I can't. There is no commands to set those when I "?" the interface. Duplex Full and Full-Duplex both say unknown command.

Any advice on using SFP's? Or setting up duplex/speed settings?

cisco_trooper

You don't normally configured speed and duplex on SFPs.

Here's a good reference for some reading: Cisco Small Form-Factor Pluggable (SFP) Transceiver Modules Maintenance and Troubleshooting - Cisco Systems

vinbuck

are you connecting at 1000 mbps physical? SFPs are usually gig interfaces and cant negotiate down to 100 mbps the way a copper port can.

DPG

Try speed no negotiate under the interface config.

nel

on our ASR9ks we are running 4.1 IOS-XR

1) try a show interface blah. Check the interface is up up.
2) Our ASRs dont auto negotiate by default. so from my experience the link doesnt work when one side is autoneg and the ASR isnt. (it was between 6500's and ASRs)
3) if their end is autoneg then the "negotiation auto" interface command will enable this for you.
4) I would check your SFP specs. just because its a Gb SFP does not mean it will run at anything else. I ran across this before when i wondered why the hell my Gb optic wouldnt run at 100mb...its because it was Gb only!
5) if you do need to set speed/duplex its the "speed x" "duplex X" interface commands.
6) check cisco config guides for OS specific commands

Some of this may be irrelevant to you, if memory serves me right those boxes run the XE platform and i dont believe the commands directly correlate between the two (could be wrong here).

Forsaken_GA

I'm guessing they have the remote end hardcoded to 100/full, effectively disabling autonegotiation on the other end, requiring you to hardcode it on your end.

Ask the engineer if that's the case, and if so, ask him to attempt allowing auto-negotiation on his end to see if that brings the link up. I'm willing to bet it does, but it'll be a full gig circuit.

This is why I like cat5 metro-E handoffs. Hate dealing with optics, and I hate dealing with Level 3 as an SP in particular.

themagicone

Thanks everyone. I passed the info about the hard coded SFP's to our project manager/engineer. This whole project went from "install 2 routers, put in config and be done" to install 2 routers, figure where the fiber is, then how to plug the fiber in, and so on... Big problem with this is the company is based in London and engineers are in India so time difference is killer for support.

gsnider

I'm going to guess that since they dropped this off as SC fiber it's multimode. You're going to need to get a multimode 100mbit SFP. Probably these 100BASE-FX SFP
You'll get a link light hooking a gig sfp up to a 100mbit fiber but as you can see it's not going to work.

themagicone

It's single mode, that much I can tell you. As for gige and 100mb, that is our problem I think. I have a call with LVL 3 in a few hours to see if they can set their router port to auto then change the speed somewhere else than the port. If not, off to find a 100mb sfp.

gsnider

According to this page that ASR 1002 doesn't support the single mode 100mbit SFP. I don't see why it would support 1 but not the other but I would go ahead and ask L3 to put a gig SFP in their equipment. I've had to do this with Centurylink before and they had no problem changing out the SFP when the customer is paying a high monthly recurring cost for a circuit.

themagicone

Well the SFP is correct. Hand off from LVL 3 is gige with rate limit of 150mb. Problem now is that they can see my mac address in Chicago DC but I can't see theirs (It is a PTP connection between MN and Chicago, LVL 3 is only handling layer 2). So are thinking now is there is a tagging, vlan or routing issue. Config is simple.

g0/0/0 (fiber port)
no ip address
no auto negotiation
mtu 9212
g0/0/0.100
encap dot1q 100
ip address 192.168.100.2 255.255.255.252


That's it! But it won't work.

creamy_stew

Are both parties aware that communication should be vlan 100?

You're probably sending something out untagged, which their equipment will pick up. Ask them which vlan they see your mac on.