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Serial 0 down, help

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UNIX72

IS-IT--Management
Sep 8, 2000
403
US
I just install a serial card into my 2500 series router and gave it ip address. When i do a sh inter s0 it keeps on stating that serial 0 is down. How do I bring it up? How can i test the card is working? Hey im new to this please excuse, thanks who helps.
 
Well.. if you installed a serial card in a 2500, you 'd better be a tinsmith since the 2500s are preconfigured. I'm guessing you ment 2600 series :) So that would be a WIC card?

If you want to test the card, make a serial loopback by taking a RJ45 plug and connecting pin 1 to 5 and 2 to 4. This will let you bring the port up and run tests.

Otherwise the port will try to come up and then go back down since nothing is attached. If this happens, sometimes the IOS will put the port into an "administrative shudown" which means you need to go into global config mode, change to the interface and type in: NO SHUTDOWN. If you look at the back of the WIC card, if the port comes up, you should get 2 green lights. Amber lights means there is an error.

Mike S
 
I have a 2524 router it does have 2 serial slots in the back serial0 and serial 1, but they were empty so i install 5-in 1 module for serial 0. It comes up when i do a sh version. Don't i need that card if i want to simulate a point to point or frame relay connection between 2 routers? thanks wybnormal.
 
Hmm ... I love this place.. always something to learn new :) I'll have to read up on the 2524's slots.

Note The five-in-one synchronous serial WAN module gets its name from the five types of signaling it supports, which include: EIA/TIA-232, EIA/TIA-449, V.35, X.21 and EIA-530. You can order a DB-60 shielded serial transition cable. The router end of the cable has a DB-60 connector; the other end of the cable has the appropriate connector for the standard interface you specify. And yes, to simulate at point to point you will need the serial port and a second router. To sim frame , you need a third router to be the frame switch.

In plain english, this means a special and probably expensive cable. That DB60 is the killer. Pacfic Cable is where I've had good luck getting some odd cisco cables made up of a reasonable price. This will also require a external CSU/DSU which will let the port come up partialy and then the loopback plug will let it come the rest of the way up.

Here is a link for some more data on the router.


Mike S
 
Do i need that DB-60 cable to get a active connection? I configure a ip address on s0 but could not ping it. So in order to simulate a frame-relay environment i need 3 routers? Does that book you refer ccie lab have excercies on this subject? Many questions sorry but i really enjoy knowing this stuff, thanks again
 
Yes, you will need that cable in order to talk to the DSU. THe CSU/DSU will provide the signaling that the router wants to see to pull the line. With the loopback plug, you can bring it all the way up complete with the protocol.

The book I review I posted does have nice excerises for this. They show how to configure a Cisco router to be the frame switch and then tie a router off each serial port ( assuming 2 serial ports) They also have a CD with the configs ready to upload if you do not want to type it all in.

Mike S
 
Sorry wybnormal, but do I need a external csu/dsu. I already have a T1 csu/dsu module for the 2524,but not install, thanks
 
OK.. yet another wrinkle :) So you have one serial card that doesnt have a DSU/CSU and just the connector? and a second card NOT installed that has a builtin DSU,CSU?

Unless the serial card has the DSU/CSU built in to it, you need the external. This seems to be what you need for the currently installed card. The second card should be ready to go with a RJ45 jack for the T1 line? THis card would let the link come up mostly, but you would still need the loopback plug to bring it all the way up. If you have two slots, you could stick in the intergrated card, get an cable/DSU for the 1st card and run a loopback cable to to each. Now you have a complete circuit that you can ping and so on.

Mike S
 
If I just want to do point to point all I need is 2 routers with at least 1 serial port for each router and back to back cable , right? Do serial cards usually come with built-in DSU/CSU? My serial card just haves a 60 pin serial connector. Again im sorry for so many questions but i want to setup a cisco lab at my home, thanks again wybnormal.
 
Most routers do NOT come with a CSU/DSU. There is an optional card for some of the Ciscos called a T1-WIC card which has the DSU/CSU built in to it. It's very popular with the 1600, 2600 and 3600 series.

Now.. with this said... if ALL you want to do it run a couple of routers back to back, you do NOT need the DSU. You DO need a special cable that runs about 35 bucks and connects two Cisco serial ports (high density serial.. not the DB60). Or you can get two V.35 cables( 1 DTE and 1 DCE) and hook the V.35 connectors together. At this point you can emulate WAN connections very nicely. I have 3 myself and I use the 3rd as a frame relay switch.

Mike S
 
Hey wybnormal I spoke to a cisco trainer he told me that you can't emulate frame-relay unless you have a real frame-relay circuit from your telco company, is this true? Thanks
 
He/she is nuts. Is that clear enough ;)

You most certainly can emulate frame using a cisco router. There is a command that turns the router into a "frame switch" where you can set the LMI type, encapsulation, DLCIs at each end AND the "frame switch". It's detailed nicely in the CCIE lab book I reviewed and I actually have set this up using 2 2500 series and a 1600 series router.
go to global config ( config t) and use the following command

!
router1(config)#frame-relay switching
!

This will enable the frame relay switch emulation

Mike S


 
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