an old friend...

i was reading an article today... from: http://blog.ipexpert.com/2009/12/14/frame-relay-switch-configuration/

Back in the “old days” of CCIE R&S, candidates were expected to know how to configure their own frame-relay switch. As time went on, and things went to CCIE R&S v3.0, that requirement went by the wayside. We were told specifically that we would not have to configure the frame-relay switch itself – Only the routers connecting into it. In fact, we were not even given access to the frame-relay switch itself. With CCIE R&S v4.0 here in full swing, it might be a good idea to revisit this old beast. We have not been told to definitely expect it (no mention on the blueprint) but we have not been specifically told not to know it either. Better safe than sorry! The good news is, a frame-relay switch configuration is relatively straight forward, and can even solidify your fundamental knowledge of how frame-relay works.

just when you thought you were out of the woods on this one frame comes back to bite your ass... thanks, joe, for stirring up some ghosts...

ah, frame...

i thought i'd dust her off a little tonight, been a while...

making the frame switch is a pain in the ass, but good practice...

here is a post i did last year...
http://insearchofthecert.blogspot.com/2011/12/frame-dash-relay.html

and below is tonight...

and there she is...

fr-sw#sh run int s1/1
Building configuration...

Current configuration : 208 bytes
!
interface Serial1/1
 no ip address
 encapsulation frame-relay
 clockrate 128000
 frame-relay intf-type dce
 frame-relay route 102 interface Serial1/2 101
 frame-relay route 103 interface Serial1/3 101
end

fr-sw#sh run int s1/2
Building configuration...

Current configuration : 208 bytes
!
interface Serial1/2
 no ip address
 encapsulation frame-relay
 clockrate 128000
 frame-relay intf-type dce
 frame-relay route 101 interface Serial1/1 102
 frame-relay route 103 interface Serial1/3 102
end

fr-sw#sh run int s1/3
Building configuration...

Current configuration : 208 bytes
!
interface Serial1/3
 no ip address
 encapsulation frame-relay
 clockrate 128000
 frame-relay intf-type dce
 frame-relay route 101 interface Serial1/1 103
 frame-relay route 102 interface Serial1/2 103
end

the tough part is getting the routes correct...
it makes it easier for me if i talk through it while building it...

of course you've turned on frame-relay switching in global config first... making all the fr-sw interfaces dce's seems obvious enough... i named r1's dlci 101, r2 dlci 102 (i like numbers to go together like peas and carrots)

so here's the talk....

int s1/1
dlci 102 coming in (it's s1/1, dlci 101's perspective)
needs to get shipped out it's connected interface (s1/2) knowing it came from  101

likewise dlci 103 coming in goes out it's connected  interface (1/3) tagged with 101...

and so on...

fr-sw#sh frame route
Input Intf     Input Dlci     Output Intf     Output Dlci     Status
Serial1/1       102         Serial1/2       101         active
Serial1/1       103         Serial1/3       101         active
Serial1/2       101         Serial1/1       102         active
Serial1/2       103         Serial1/3       102         active
Serial1/3       101         Serial1/1       103         active
Serial1/3       102         Serial1/2       103         active

so adding another router, another interface and another dlci is a piece of cake...

dlci 104 coming in needs to get shipped to it's interface tagged with the dlci that's shipping it..

i have to use s2/1 for dlci 104 because i'm  out of corresponding numbers...

on s1/1(dlci 101)

frame route 104 int s2/1 101

for s1/2(dlci 102)

frame route 104 int s2/1 102

for s1/3

incoming 104 goes out s2/1 as 103

for s2/1 (104) you'll have to add three route's

incoming 101 goes out s1/1 as 104
incoming 102 goes out s1/2 as 104
incoming 103 goes out s1/3 as 104

and 104 is already spoken for on it's own interface...

fr-sw#sh fram route
Input Intf     Input Dlci     Output Intf     Output Dlci     Status
Serial1/1       102         Serial1/2       101         active
Serial1/1       103         Serial1/3       101         active
Serial1/1       104         Serial2/1       101         active
Serial1/2       101         Serial1/1       102         active
Serial1/2       103         Serial1/3       102         active
Serial1/2       104         Serial2/1       102         active
Serial1/3       101         Serial1/1       103         active
Serial1/3       102         Serial1/2       103         active
Serial1/3       104         Serial2/1       103         active
Serial2/1       101         Serial1/1       104         active
Serial2/1       102         Serial1/2       104         active
Serial2/1       103         Serial1/3       104         active

suitable for framing...