SNA to Ethernet via 56k

[r]

trying to establish a connection on  an ibm 3745 controller via two IBM 5822 modems to a cisco 2600 router using sdlc encapsulation secondary bridging data from the serial port to the E/Net port to run the 3270 client ???

[vmiller]

Its been a while since I looked at this stuff:

Is there a router in front of the 3745 ?

you can start looking at this link for how to configure the ethernet side of the remote router.

you might want to veify that you have an IOS that supports this stuff.

http://www.cisco.com/en/US/docs/ios/11_3/ibm/configuration/guide/bcdlsw.html#wp2130

[r]

Thanks for your reply, This is a single router deployment and the 3745 is in a primary role, we have established SDLC communication with the encap secondary command on the serial interface,however when using this option you loose the DLSW. Issue is how to SW- route or bridge to  the e/net  port. I do have enterprise IOS on the 2600...

[paolo bevilacqua]

Friendly advice - unless you've done this stuff before and understand exactly how all the parts involved work, hire someone that knows - is not beginners job.

[r]

Thanks for the reply,while I'm not an expert I must agree its not for beginners a little more info. This is a single router deployment and the 3745 is in a primary role, we have established SDLC communication with the encap secondary command on the serial interface,however when using this option you loose the DLSW. Issue is how to SW- route or bridge to  the e/net  port. I do have enterprise IOS on the 2600...

[vmiller]

What are you using as a remote peer for DLSW? Did you try a bridge group for the ethernet? My own long ago experience had a remote peer device at the back end to create the dlsw connection.

[r]

In this case I cannot use DLSW you loose that option with the SDLC in a secondary role--

My configuration  3745 controller -- 5822 modem -- 56k serial link --- 5822 modem -- cisco 2600 ent. IOS -- laptop e/net running 3270 emulation.. The 3745 is Primary

I have the modems configured and when the serial link is in secondary I excange SNRM messages and the line on the controller is active pending the Physical Unit.. When placing the serial link as Encap SDLC SECONDARY the serial interface populates with a 'traddr" just not sure get this to bridge this to  the e/net...

[r]

What are your thoughts on this -- think it will work on one router interface serial 0 encapsulation sdlc-secondary sdlc address c1 sdllc traddr 0110.2222.3300 222 1 100 sdllc partner 4000.0122.0001 c1 interface loopback 0 ip address 1.0.0.1 255.255.255.0 Router B source-bridge ring group 100 source-bridge remote-peer 100 tcp 1.0.0.1 source-bridge remote-peer 100 tcp 5.0.0.1 source-bridge transparent 100 13 1 4 interface ethernet 0 ip address 5.0.0.1 255.255.255.0 bridge-group 4 bridge 4 protocol ieee

[vmiller]

Is RSRB even still available? Yikes that brings back bad memories.

I don't see how this will work with just one router. While the router can mimic

some of the behaviors of a cluster controller, It needs a peer router at the other

end to de-encapsulate traffic before it goes to the Front end processor. Since you have

modems in the design, i'm speculating that the IBM modem is LIC attached with a

LIC4 (its been a while). I don't know of anything in that piece of the NCP that can do

what you want.

[mwinnett]

Little bit hacked and untested but the below should work. Note that IOS config for dlsw is almost always in token-ring format (ethernet redundancy is the only exception). In the example below, the PC mac would be the ethernet format of 4000.9999.0100 (which is 0200.9999.8000) and would have a dest-mac which would be the ethernet format of 4000.3333.4400 (0200.cccc.2200). This assumes configured sdlc address of 0x01 (use the configured value in the fep). Here the router is supplying clock and is not configured for nrzi.

dlsw local-peer

dlsw bridge-group 1

!

interface Ethernet0/0

no ip address

bridge-group 1

!

interface Serial2

mtu 4400

no ip address

encapsulation sdlc

no keepalive

clockrate 9600

sdlc role secondary

sdlc vmac 4000.3333.4400

sdlc address 01

sdlc dlsw partner 4000.9999.0100  inbound

sdlc dlsw 1

EXplanation of bit-swapping mac-address between ethernet and token ring formats at

http://www.cisco.com/web/tsweb/tools/bitswapping/index.html

I think that rsrb will not be in IOS 15.x. Dlsw is the way to go here, but we'll have some stuff come out of the woodwork when rsrb is finally not available.

Let me know if you need further help

Matthew

[r]

Thanks for the reply, a little confused about the vamc and partner mac -- are these just arbituary ( made up addresses) ??In my case the sdlc address is 40

[mwinnett]

What is the mac-address of the PC on the ethernet ? Is it configured to connect to a destination mac-address ? If so, what is it ?

Matthew

[mwinnett]

James

Sorry for the delay in replying. The forum backend s/w has been upgraded and it looks like there is a defect whereby we don't always get notifications of any responses.

The PC will be configured with a target mac-address and will have a mac-address for its own ethernet interface. The partner address will be the PC interface mac-addr in token ring format. The vmac is the target mac-address configured in the pc. The router modifies the last byte of the vmac with the sdlc address. Therefore, using the example below, the PC will have to configure the target mac-address as

4000.3333.4440. In ethernet format, this will be 0200.cccc.2202

interface Serial2

encapsulation sdlc

sdlc role secondary

sdlc vmac 4000.3333.4400

sdlc address 40

sdlc dlsw partner 4000.9999.0100  inbound

sdlc dlsw 40

If you want to discuss by phone, ping me privately your number and timezone and I can call.

Matthew

[wlt]

I know tihs is years later but I am doing the same and I have few questions to different posters. James, what cable is being used between the 2600 and 5822, DB60-DB25 or DB60-V.35? Matthew can you explain on the vmac and partner adresses, I am not clear on that portion? Thanks!

[mwinnett]

William, conenction over dlsw is essentially mac-address to mac-address. When you terminate sdlc into dlsw, you still need to have a source mac-address and a destination mac-address. 99% of the time, sdlc attached devices are low speed terminals (ATMs) at the branch site. The destination will be your target at the far end of the dlsw peer, this is normally an address on a snasw router, cip router, IBM front end, IBM mainframe OSA etc. Ths address will be the sdlc partner address. As sdlc devices do not have a mac-address we need to invent (virtualise) one. One complication is that you can have multiple sdlc devices on the same line. Therefore, the sdlc end virtual mac-address is the vmac address. The last byte must be coded as "00" and the router will replace this with the sdlc address (eg: "40" in the example). In the config above, dlsw will see a conmnectionm from 4000.3333.4440 -> 4000.9999.0100. Matthew