BGP Professional Lab 1

Lessons Discussion
21

Hello, this is really well done lab. I am having an issue getting ping to work down the tunnel. Any ideas. My source and destination addresses match the values as specified in the lab as well as the internet address applied to the tunnel itself on both R5 and R9. I have modeled your lab in CML. The tunnel is showing up up on both sides, but pings are failing. I have checked, double checked, and tripled checked my entries but cannot see any value different from those specified in the lab answer. Any suggestions would be most appreciated.

22

Please disregard. I found the problem. It helps to turn up the interfaces on R8. Duh!

23

Hello Richard

:rofl::laughing::grinning_face: Yes, it does help to bring up the interfaces! Thank you, however, for your kind words about the lab. We’re really excited that it is helpful for you! If you need any further help, let us know!

I hope this has been helpful!

Laz

24

This is a great lab, tons of hands-on practice, thanks a lot!

My question is about the topic 3.4.9.2 Requirement prefix 123.45.0.0/17

We use No-Export community with the network 123.45.0.0/17 however in ACL we use the wild card mask 0.0.31.255

Shouldn’t it be 0.0.127.255?

Vladimir

25

Hello Vladimir

Thanks for sharing, and I’m glad that you find the lab useful!

Yes, you’re absolutely right. It should be 0.0.127.255. I will let @ReneMolenaar know to make the change.

Thanks again for pointing it out!

Laz

1 Like
26

Very cool lab - thanks for putting this together!

One typo I believe in 2.4.17: “Configure BGP next hop tracking on R2 so that the next hop IP addresses of R2 and R3 are actively tracked.” That should say “tracking on R1” instead of “on R2”

Also FWIW (which is nothing), although your Regex is simpler to understand, I got it in 2 lines instead 3 =)

permit 4567$
deny 4567\_
permit .\*

vs.

deny 4567\_(\[0-9\]+)
permit .\*
1 Like
27

Hello Nathan

You are correct, I will let @ReneMolenaar know to make the appropriate modifications. Thanks for pointing that out!

Awesome! That’s perfectly fine! It is more efficient and 100% valid. However, as you mention, the statements in the lab are a bit more understandable. The goal, of course, is to be as efficient as possible, but also to be as clear as possible, so that when you see your config in the future, or when another engineer takes a look at the config, it will be immediately understandable what you did.

So it’s a tradeoff. In this case, both are valid, but you must consider: is it worth it to put in an extra command just to have your intent much clearer in the config itself?

I know it’s a relatively insignificant command difference, but the principle involved is worth expanding on, and that is why I’m spending a bit more time on it. Thanks for the opportunity!

I hope this has been helpful!

Laz