TL; DR: How can I connect two old AS/400 machines via SNA when the only transport mechanism between the physical locations is IP? AnyNet isn't an option, see below.
A friend of mine and I have two IP networks linked together with an IPSEC Site2Site-VPN utilizing Cisco-Routers. Works like a charm. Since I have more VPN uplinks, a Cisco ASA filters out unwanted traffic flows at my side.
We also run two old IBM AS/400 9401-150 with OS/400 V4R5. One at my site, one at his'. We use distinct SNA network id names (instead of the default "APPN"). The two machines are linked together with the AnyNet-Capability of OS/400. Basically this works,
sndnetmsg are nice to play with. But I suspect that the Cisco ASA in between loses track of the established TCP or UDP session sometimes. Sometimes, the SNA-Session backed by IP recovers, sometimes not. To get the SNA connection to a working state again, I need to vary off the controller descriptions on both sides; most often with the force-parameter, since one side sometimes doesn't permit varying off the *ctld "at this time".
Anyway, I want to get rid of AnyNet and use Enterprise Extender.
Unfortunately, EE isn't available in V4R5, it's just too old. But Cisco IOS is capable of doing this, on certain platforms with a certain feature set in a firmware image.
I do have two Cisco 2500 at hand with the needed IBM Networking Image. So I configured IOS to build a link via Ethernet LLC to my AS and the same mirror-like at my friends site. Configuration excerpt:
snasw event implicit-ls port cpcp snasw cpname POCNET.DSLRTR snasw port LAN GigabitEthernet0/0.1 snasw port TFR hpr-ip Loopback0 vnname POCNET.POCNET snasw link NIBBLER port LAN rmac 0004.acde.9369 nns snasw link FRIENDRT port TFR ip-dest 172.31.178.65
The APPC *ctld on the AS' are created automatically and run fine. I can successfully aping both adjacent routers from the respective AS/400.
I also added two loopback interfaces on the router, defined another port (TFR) and built a link between these two. Link is up, no sessions are started. Somewhat expectable.
SNA Links HPR Link Name State Port Name Adjacent CP Name Node Type Sess Sup --------- -------- --------- ---------------- ------------ ---- --- 3> FRIENDRT Active TFR FRIEND.FRIENDRT End Node 0 Yes 4> NIBBLER Active LAN POCNET.NIBBLER Network Node 2 Yes
This is the point where I'm stuck. I expect to get LU6.2-Sessions from one AS via the adjacent router to the other router which get finally forwarded to the destination AS. This isn't happening.
I poked in the fog a bit, tested with
aping to the other side's cisco router and the other side's AS/400, but no avail:
- Added an entry to the QAPPNRMT configuration lists of both machines to destination *any with the respective remote net id. The remote cpname is the adjacent cisco router.
- An APPC *devd is automatically created and varied on, though.
- Created an APPC *ctld type *vrtappn but didn't find how to tell this *ctld to route the session via the adjacent cisco router.
The configuration is in parts derived by studying IBM "iSeries Networking APPC, APPN, and HPR" and Cisco "Bridging and IBM Networking Configuration Guide 12.4".
First, if I'm wrong here, please tell me which subsite of StackExchange is more appropriate. Since all components I use are nearly 20 years old, it made sense to me to ask here.
Please refrain from pointing out to use IP as transport between the machines. First, some applications just have no option to utilize IP as transport. Second and most important: These boxes are old and slow and a single ftp session over the 10Mbit/s NIC brings these boxes down to their knees. SNA transport is much more lightweight. That's the main intention for me, trying to utilize SNA, or to be more precise, a PU2.1 connection between the AS' and their routers while the data itself (utilizing LU6.2 between the AS') is transported via HPR/IP between the cisco routers.
Maybe I'm completely on the wrong track and that's just not how EE works. The entire SNA stuff is rather complicated and I still have an awful lot of puzzle pieces still waiting to fall in place to show a picture I can understand. :-)
Would anyone please be so kind and create the tags AS400 and Cisco? Since I'm a newbie here, I'm not allowed (yet).