interface command doesnt accept Serial 0

fusebox

Hi there.

I have recently started studying for the CCNA, and have also bought a home lab to study and get hands on experience.

I have a question. I was going through the RIP router configuration techlab on this website and when I get to the part where I have to configure the Serial connection, I cant seem to do so.

normally how this is supposed to be done is by typing in privaledged mode
RouterName(config)#interface Serial 0

But my router wont accept the name Serial.... When I type in "interface ?"
It shows Ethernet, BRI etc but no Serial. I have a feeling my serial connections have been converted to BRI ports.... is there any way I can reverse these.

my routers are two Cisco 2503.

Any help and feedback would be greatly appreciated.
Thanks.

keenon

erase the the config would be my thought.. when i got my routers they had async interfaces on them... use "write erase" command then reload router.. it should work fine

Nocturnal

Do a "show int" command to see what you've got. Use the ? help features.

fusebox

write erase is a safe command to use then?

What ive been doign thus far only is "erase startup-config"


in global config mode when I type in the following "interface ?" I get the following;

RouterA(config)#interface ?
Async Async interface
BRI ISDN Basic Rate Interface
BVI Bridge-Group Virtual Interface
Dialer Dialer interface
Ethernet IEEE 802.3
Group-Async Async Group interface
Lex Lex interface
Loopback Loopback interface
Null Null interface
Tunnel Tunnel interface
Virtual-Template Virtual Template interface

As you can see Serial 0 nor Serial 1 is displayed...

tunerX

How much memory do you have, with some models of router, some interfaces may not show up unless you have the memory to initialize them. I haven't ever seen this with the 2500 series but maybe you have some bad memory. You need to watch every line on boot-up to see if there are any errors.

Do a "show version" and see if you system sees the serial interfaces. Check for the serial interfaces and also check the amount of RAM available. The motherboard has 2MB of RAM on the motherboard. I believe the on board memory is responsible for interface IO.

Do a "show memory summary" and check if you have at least 2MB of memory for IO, otherwise you do not have enough to initialize the serial interfaces.

cisco 2511 (68030) processor (revision M) with 14336K/2048K bytes of memory.
Processor board ID 15665246, with hardware revision 00000000
Bridging software.
X.25 software, Version 3.0.0.
SuperLAT software (copyright 1990 by Meridian Technology Corp).
TN3270 Emulation software.
1 Ethernet/IEEE 802.3 interface(s)
2 Serial network interface(s)
16 terminal line(s)
32K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read ONLY)

Configuration register is 0x2102

fusebox

The following is what I get when I type in Show memory


cisco 2500 (68030) processor (revision N) with 6144K/2048K bytes of memory.
Processor board ID 11835396, with hardware revision 00000001
Bridging software.
Basic Rate ISDN software, Version 1.0.
1 Ethernet/IEEE 802.3 interface(s)
1 ISDN Basic Rate interface(s)
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash partition 1 (Read ONLY)
8192K bytes of processor board System flash partition 2 (Read/Write)

Configuration register is 0x2102



Umm when I type in show memory summary, the first output that comes out is this;


Router#show memory summary
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor 3CB94 6038636 698728 5339908 5301400 5333188
I/O 600000 2097152 285492 1811660 1811660 1811660


Obviously its not showing the serial interfaces at all... So what should I do?
The thing is I actually bought two 2503 routers and both are showing the same symptoms...

Also when I do show interfaces, it goes through three BRI ports, namely BRI0, BRI0:1 and BRI0:2. So is it possible that my serial ports are acting like they're BRI ports??

Nocturnal

Check this page out:

http://www.cisco.com/univercd/cc/td/doc/pcat/2500.htm

Maybe you have what they call a "mission specific" router, in which the serial interfaces are disabled; in the chart they provided, the 2503 was shown to have both serial ports disabled....here's a cut 'n paste of the text above the chart where I saw that information:



"Mission-specific routers are entry-level routers that are based on standard Cisco 2500 hardware. However, mission-specific routers contain less memory than standard models and run reduced software images designed for CFRAD, LAN FRAD, and ISDN applications. These reduced software images disable unused ports. Mission-specific routers can be upgraded to full standard-model functionality by purchasing additional software and memory."



If this is the case, don't let it get you down too much; I bought a 2524 a few months ago that wasn't quite what I expected...I just chalk it up as a learning experience...after all we buy these things to learn...sometimes the path is a little muddy. I know you can get memory pretty cheap on Ebay. I've been thinking of opening up my 2524 because it could use a memory upgrade.

Also, if you do a "show ver" you could cross reference the IOS image at Cisco's website to verify this hypothesis.

Hope this helps! I'm still intrigued about the extra BRI intefaces....best of luck, brother; I'm in your corner!!

fusebox

Ive emailed the person from whom I bought the routers, to see if he knows anything about it... (hasnt yet gotten back to me.. been a couple of days)

I'll open one of the routers up to see if im short on memory...

The other thing is that these routers are running IOS ver: 11.2

Now if I were to upgrade to a 12.x... does anyone know what the costs are for doing this and what roughly the procedure is also?

Anything else I find out... I'll keep you guys posted.
Im hoping its an easy fix...... ie: its a mission specific router

nethead

Can you post up what the full IOS image name is and we may be able to help identify if its the image causing the problem.

In regards to the BRI interface this is just one interface, BRI0 represents the physical interface (ie the one physical port that you have) and BRI0:1 & BRI0:2 represent the two (64k) B channels that are provided on basic rate ISDN.