DEBUGGING
Key Commands Shows and Debugs
Config-register 0x2102
> o
Bits:
15 Diagnostic mode disabled
14 IP Broadcast do not have network numbers
13 Boot default ROM software if net boot fails
12-11 Console Speed 9600-4800-2400-1200
10 IP boradcasts with ones
08 Break disabled
07 OEM disabled
06 Ignore Configuration disabled
03-00 Boot file/location
To see the config register settings:
> e/s 2000002
> q
To set:
O/r 0x2102 To reload: > i
Additional Commands
On 4500, 4700, 36XX, 72XX, 75XX: Confreg
For cables, use the "show controller" command to see
if DCE or DTE. Do NOT necessarily trust the labels.
Show frame lmi:
Deleted: trouble talking to the frame switch
Inactive: Other side not working right
Active: You're good to go.
Encapsulation failed:
On frame, do debug frame packet and make sure you're
not getting "no map to destination". Use frame map.
On ethernet, means no arp reply, so can't encaps.
Do a debug arp
• OSPF timers: Use the "show ip ospf interface s
0" command to check the timers and make sure
they match.
• Use "ip ospf demand-circuit" on DDR links
• If decnet is involved, remember that it takes
over the MAC address on ethernet. Check for ipx
• If bgp has to be sync, it HAS to redistribute
into the IGP
• Always specify the node # in ipx (ipx routing
A.B.C)
• Remember the next-hop reacheability requirement
in BGP. Use next-hop-self on neighbor statement
to alleviate.
Spot The Issue Notes
. DEBUGGING
Key Commands Shows and Debugs
Config-register 0x2102
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