CCIE Pursuit Blog

December 18, 2007

Internetwork Expert Volume II: Lab 3 – Section 2

Section 2 – Frame Relay – 8 Points

2.1  Hub-and-Spoke

This section was easy.  If you’ve run through the IE Volume I Frame Relay labs you will be pretty familiar with the different Frame Relay variations.  That said, the first task threw me for a bit of a loop because I had a difficult time interpreting it: 

“Do not use dynamic layer 3 to layer 2 mappings over these Frame Relay connections.”
“Do not configure static layer 3 to layer 2 mapping between r2 and r4”

So….should we have connectivity between r2 and r4 (hubs) at all?  Does the second sub-task allow us to map r2 and r4 to r1?  Answer: no.  We are not supposed to be able to communicate from spoke to spoke.  A later OSPF task will fix this.

I had to reboot r2 and r4 because there were dynamic frame mappings on those routers already.  I’ve run into this in all of the labs with initial configurations.  I find it easiest to disable Frame Relay Inverse-ARP and then reload the router.

Before reload:

r2#sh frame map
Serial0/0/0 (up): ip 136.1.15.1 dlci 201(0xC9,0x3090), dynamic,
              broadcast,, status defined, active
Serial0/0/0 (up): ip 136.1.245.5 dlci 205(0xCD,0x30D0), static,
              broadcast,
              CISCO, status defined, active

r4#sh frame map
Serial0/0 (up): ip 136.1.245.5 dlci 405(0x195,0x6450), static,
              broadcast,
              CISCO, status defined, active
Serial0/0 (up): ip 136.1.15.1 dlci 401(0x191,0x6410), dynamic,
              broadcast,, status defined, active

For some reason (did I anger the router gods?) I still had a dynamically mapped PVC on r2 and r4 (spokes) – even though I had disabled Frame Relay Inverse-ARP and reloaded:

r2#sh frame map
Serial0/0/0(up): ip 136.1.15.1 dlci 201(0xC9,0x3090), dynamic,
              broadcast,, status defined, active
Serial0/0/0 (up): ip 136.1.245.5 dlci 205(0xCD,0x30D0), static,
              broadcast,
              CISCO, status defined, active

r2#sh ver | b uptime

r2 uptime is 3 minutes
System returned to ROM by reload at 18:47:24 UTC Sat Dec 15 2007
System image file is “flash:c2800nm-adventerprisek9-mz.124-11.T2.bin”
—output truncated—

r2#sh frame map
Serial0/0/0(up): ip 136.1.15.1dlci 201(0xC9,0x3090), dynamic,
              broadcast,, status defined, active
Serial0/0/0 (up): ip 136.1.245.5 dlci 205(0xCD,0x30D0), static,
              broadcast,
              CISCO, status defined, active

r2#sh run int s0/0/0
interface Serial0/0/0
 ip address 136.1.245.2 255.255.255.0
 encapsulation frame-relay
 frame-relay map ip 136.1.245.5 205 broadcast
 no frame-relay inverse-arp

r2#clear frame inarp

r2#sh frame map
Serial0/0/0 (up): ip 136.1.245.5 dlci 205(0xCD,0x30D0), static,
              broadcast,
              CISCO, status defined, active

That was VERY odd.  I’ve never had a dynamically mapped FR PVC remain after disabling FR Inverse-ARP and rebooting.  Furthermore, I’ve never been able to successfully clear a dynamic mapping by using “clear frame-relay inarp” [note: DOC shows “clear frame-relayinarp” but router takes “clear frame-relay inarp” (hypen in first example, space in second)]

2.2 Point-To-Point

2.3 Point-To-Point

Other than that bit of Frame Relay oddness, the remainder of the tasks in this section were very simple.  The IE answer has nice write up on pinging with source routing.

Advertisements

1 Comment »

  1. I’ve had good luck with “shut” and “no shut”- definitely faster than reloading the devices themselves.

    Comment by Tobias Sorensen — January 3, 2008 @ 4:06 pm | Reply


RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Blog at WordPress.com.

%d bloggers like this: