System information

Troubleshooting IBM 10-241
SDLC: Sessions Fail over Router Running STUN
Possible Problem Solution
Peers are not open
Step 1 Use the show stun exec command to see whether the peers are open. If the peers are
open, one of the other problems in this table is probably the cause.
The following is sample output from the show stun command:
Router# show stun
This peer: 131.108.10.1
Serial0 -- 3174 Controller for test lab (group 1 [sdlc])
state rx-pkts tx-pkts drops poll
7[ 1] IF Serial1 open 20334 86440 5 8P
10[ 1] TCP 131.108.8.1 open 6771 7331 0
all[ 1] TCP 131.108.8.1 open 612301 2338550 1005
In this display, the first entry reports that proxy polling is enabled for address 7 and
serial 0 is running with modulus 8 on the primary side of the link. The link has
received 20,334 packets, transmitted 86,440 packets, and dropped 5 packets.
Step 2 If the peers are not open, use the debug stun command on the core router to see
whether the peers are trying to open. Peers do not open if there is no traffic on the
link.
Caution: Do not enable debug commands on a heavily loaded router. Doing so can
cause performance and connectivity problems. Use a protocol analyzer or show
commands instead.
Step 3 If you do not see the peers trying to open, use the show interface exec command to
make sure the interface and line protocol are both up. If they are not both up, there
could be a link problem. Proceed to the problem “SDLC physical or link-layer
problem” later in this table.
Step 4 If the peers are trying to open, use the show running-config privileged exec
command to make sure that the stun route and other STUN configuration
commands are configured correctly. Reconfigure the router if necessary.
Step 5 Use the debug stun packet privileged exec command on the core router. Look for
SNRMs or XIDs being sent.
Step 6 If you do not see SNRMs or XIDs, there is probably a basic link problem. See the
problem “SDLC physical or link-layer problem” later in this table.
Step 7 Check to make sure that there are not other network problems occurring, such as
interface drops, buffer misses, overloaded Frame Relay switches, and IP routing
problems.
SNRMs or XIDs not
sent
Step 1 Use the show stun command to see whether the peers are open. If the peers are not
open, see the preceding problem in this table.
Step 2 If the peers are open, use the debug stun packet privileged exec command on the
remote end. Check for SNRMS or XIDs from the primary arriving as NDI packets.
Step 3 If SNRMs or XIDs are arriving, proceed to the next problem in this table.
Step 4 If SNRMS or XIDs are not arriving, use the debug stun packet command on the
core router to see whether SNRMs or XIDs are being sent.
Step 5 If the core router is not sending SNRMs or XIDs, make sure that the physical and
link layers are operating properly. See the problem “SDLC physical or link-layer
problem” later in this table.
Step 6 If the core router is sending SNRMs or XIDs, use the show running-config
privileged exec command to make sure the stun route command is properly
configured on the router.
Step 7 Check to make sure that there are not other network problems occurring, such as
interface drops, buffer misses, overloaded Frame Relay switches, and IP routing
problems.