Re: connecting ethernet to token ring

aborres · ‎10-11-2004

I'm having trouble trying to configure cisco 2612 router to connect SNA server to datacenter host. please refer to connectivity below.

SNA server--eth----router--t/r--control unit--modem-SDLC---modem---FEP

the controller unit has token ring card installed on it and it's connected to router's t/r port..i configured the router with SR/TLB but no success, what we did we temporarily removed the router and add token ring adapter on the same SNA server then connect direct to control unit and it's work but we need to implement the connectivity shown above..thanks

mbinzer · ‎10-12-2004

Hi,

a very simple question. What dmac did you use on the sna server when it was ethernet attached?

If you say it works with a tokenring adapter what damc was used in this example?

You need to bitswap the dmac when you have the sna server ethernet attached. Some do try always both canonical and non-canonical, some dont.

Do you have a chance to take a sniffer trace on the tokenring when you try to do sr/tlb to see what frames are beeing exchanged between the sna server and the tr controler.

The only other point you may need to look at is the mtu size. If you connect an ethernet like described above your mtu on the ethernet is limited to 1500. So make sure that the tokenring router and control unit are ok with that.

Also the configuration you used and the ios version on the cisco2600 would help to get some more ideas what might go wrong.

thanks...

Matthias

aborres · ‎10-13-2004

Hi Matthias,

I did bitswapped the dmac configured on the SNA server from 400013052100 to 0200C8A08400 but the same problem (connection pending), is there any tools or utility wherein we can check whether our router is forwarding DLC protocol to the control unit or not.

Thanks;

Ador

mbinzer · ‎10-13-2004

Hi,

debug source error

debug source event

debug source bridge

Also a sniffer on the tokenring should show you what goes on.

If you dont have a sniffer take a look at ethereal:

http://www.ethereal.com/

it is free and works very well.

Besides that i would advice to open a case with cisco tac and work the issue in detail. This is supposed to work and if it does not work than we need to find out why.

thanks...

Matthias

aborres · ‎10-13-2004

Hi Matthias,

Thanks for the reply, one more thing, I got utility to ping the dmac from ethernet station..result is shown below.

Sending TEST Commands to NIC MAC 400013052100

Request timed out after 500ms

Test Commands were not acknowleged

Flipping MAC bits. New MAC is 0200C8A08400

Reply from 0200C8A08400: time <0ms

Sent 4, Received 4, Lost 0 (0% Loss)

please advise if the above ping result is normal or not...

Thanks,

Ador

mbinzer · ‎10-14-2004

Hi Ador,

i dont know the tool you are using but if that result is correct than it seems as if the "ping" goes through when you use the ethernet format mac address. That would indicate that the router is forwarding those frames in both directions.

It looks like as if you are sending sna test frames with your ping utility and you expect a test final or something back.

I think the best way to go on is to take a sniffer on your tokenring and see what comes and goes and then try your ping utility, have a look how it looks and try a login from your server.

thanks...

Matthias

aborres · ‎12-13-2004

Hi Matthias,

please check the attached captured frames using ethereal. we are still facing problem connecting sna server using ethernet..

Thanks,

Ador

mbinzer · ‎12-13-2004

Hi,

based on the prior conversations i assume the following topology:

SNA server--eth----router--t/r--control unit--modem-SDLC---modem---FEP

So in case of your tokenring attached sniffer trace i think the server was tokenring attached instead of ethernet.

I assume that the sniffer was always in the "right" tokenring based on above topology.

In both traces there are no rif fields in the sna frames from and two the sna server. I filtered for

4000.1305.2100.

I would assume always to see a rif field in the frames on the right tokenring.

In the first, the working case, when the client is on tokenring you should have source bridging configured and then we certainly would see a rif field.

In the case when the client is ethernet attached you should have sr/tlb configured and we would then also see a rif field in the sna frames.

Are you simply doing transparent bridging between those two tokenrings and then also between the ethernet and the tokenring?

I guess we will need to look at your currnet configurations first to understand how this is currently configured.

It is most likely also a good idea to open a case with the tac at that point.

thanks...

Matthias

aborres · ‎12-14-2004

Hi Matthias,

working topology:SNA server with 2 NIC ethenet and T/R

--eth-SNA-t/r---control unit-modem--sdlc--modem--FEP

with router:not working

SNA-eth-router-t/r-control unit-modem-sdlc-modem-FEP

please checked the router config below, thanks

Current configuration : 686 bytes

!

version 12.1

no service single-slot-reload-enable

service timestamps debug uptime

service timestamps log uptime

no service password-encryption

!

hostname Router

!

enable secret 5

!

ip subnet-zero

no ip routing

!

source-bridge ring-group 20

source-bridge transparent 20 10 2 5

!

interface Ethernet0/0

ip address 10.10.50.2 255.255.255.0

no ip route-cache

bridge-group 2

!

interface TokenRing0/0

no ip address

no ip route-cache

ring-speed 16

source-bridge 5 2 20

!

ip default-gateway 10.10.50.1

ip classless

ip http server

!

bridge 2 protocol ieee

bridge 2 bitswap-layer3-addresses

!

line con 0

line aux 0

line vty 0 4

password

login

Ethernet0/0 is up, line protocol is up

Hardware is AmdP2, address is 000e.3853.fae0 (bia 000e.3853.fae0)

Internet address is 10.10.50.2/24

MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:00, output 00:00:01, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue :0/40 (size/max)

5 minute input rate 1000 bits/sec, 2 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

3789 packets input, 364786 bytes, 0 no buffer

Received 2964 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 input packets with dribble condition detected

354 packets output, 39668 bytes, 0 underruns

0 output errors, 0 collisions, 1 interface resets

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

TokenRing0/0 is up, line protocol is up

Hardware is HAWKEYE, address is 0070.1cca.5f87 (bia 0070.1cca.5f87)

MTU 4464 bytes, BW 16000 Kbit, DLY 630 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation SNAP, loopback not set

Keepalive set (10 sec)

ARP type: SNAP, ARP Timeout 04:00:00

Ring speed: 16 Mbps

Duplex: half

Mode: Classic token ring station

Full duplex capable

Source bridging enabled, srn 5 bn 2 trn 20 (ring group)

spanning explorer disabled

Group Address: 0x00000000, Functional Address: 0x0800011A

Ethernet Transit OUI: 0x000000

Last Ring Status 00:05:14 (0x2000)

Last input 00:00:00, output 00:00:03, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue :0/40 (size/max)

5 minute input rate 1000 bits/sec, 1 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

2794 packets input, 449251 bytes, 0 no buffer

Received 962 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

390 packets output, 31117 bytes, 0 underruns

0 output errors, 0 collisions, 8 interface resets

0 output buffer failures, 0 output buffers swapped out

0 transitions

mbinzer · ‎12-14-2004

Hi,

i think your sr/tlb statement is not correct:

you have configured:

source-bridge transparent 20 10 2 5

20 is the source bridge virtual ring group

10 is the pseudo ring, this is the ring number used

to represend the ethernet from the tokenring

2 is the bridge number between 20 and 10

5 is the transparent bridge group tied into the

source bridge environment

however you dont have a transparent bridge-group 5. You have transparent bridge group 2.

your statement should look like this:

source-bridge transparent 20 10 2 2

additional i would add under the tokenring interface

the command:

source-bridge spanning

just in case your end systems are sending single route explorers. If they do you must enable the tokenring inteface to accept single route (spanning tree) explorers.

thanks...

Matthias

aborres · ‎12-17-2004

Hi Matthias,

from the attached show lnm station and show source-bridge. 4000.1305.2100 is the dmac configured on SNA server when it is connected thru token ring and it has t/r mac 4000.1305.2102. when connected thru ethernet, I did bitswapped the dmac to 0200.C8A0.8400 but still giving connection pending, is there any required modification at the host side if we want to connect the SNA server thru ethernet?

thanks,

Ador

mbinzer · ‎12-20-2004

Hi,

in general the host does not know on what meadia you are. Unless you have some sort of a dialout configuration the host normaly does not have any mac address knowledge about the client.

If i assume that the sr/tlb statement is correct, and you can see the correct addresses in the transparent bridge table from the ethernet end and also in the source-bridge environment.

show bridge

show source

show rif

than i guess you are back to use a sniffer and see if you get any communincation between those two devices and if so how far you get.

You should see frames with a rif field going from and to the configured pseudo ring when you look at it from the tokenring perspective.

Is your tokenring/sdlc converting device understanding rif's?

I am a littlebit out of idea's right now.

thanks...

Matthias