Information Technology Reference
In-Depth Information
Table10-10 SDLC: Client Cannot Connect to Host over Router Running SDLLC (continued)
Possible Problem
Solution
FEP not replying
to XID
1.
With the
debug sdllc
and
debug llc2 packet
privileged exec
commands enabled on the router, check to see whether the
FEP is replying to XID frames from the router.
2.
If the FEP is responding, proceed to the next problem in this
table.
3.
If the FEP is not responding, check the XID values
configured by the
sdllc xid
command on the router. The
values for IDBLK and IDNUM on the router must match the
values in VTAM on the FEP. The following is the syntax for
the
sdlc xid
command:
sdlc xid
address xid
Syntax description:
•
address
—Address of the SDLC station associated with this
interface.
•
xid
—XID that the Cisco IOS software will use to respond to
XID requests that the router receives. This value must be 4
bytes (8 digits) in length and is specified with hexadecimal
digits.
Example:
The following example specifies an XID value of 01720002 at
address C2:
interface serial 0
sdlc xid c2 01720002
Make sure that the XID information on the hosts is properly
defined. If a 317X device is a channel-attached gateway, the
XID must be 0000000 for IDBLK and IDNUM.
4.
Host problem
Check for activation, application problems, VTAM and NCP
misconfigurations, configuration mismatches, and other
problems on the IBM host.
1.
FEP=front-end processor
2.
XID=exchange of identification
Virtual Token Ring Addresses and SDLLC
The
sdllc traddr
command specifies a virtual Token Ring MAC address for an SDLC-attached device
(the device that you are spoofing to look like a Token Ring device). The last two hexadecimal digits of
the virtual MAC address must be 00. The router then reserves any virtual ring address that falls into the
range xxxx.xxxx.xx00 to xxxx.xxxx.xxff for the SDLLC serial interface.
As a result, other IBM devices on an internetwork might have an LAA that falls in the same range. This
can cause problems if you are using local acknowledgment because routers examine only the first 10
digits of the LAA address of a packet (not the last two, which are considered wildcards).
