This is a thread from about a year ago that specifies the configuration on a CISCO router for bridging DTC traffic. I used it successfully for two remote DTC-48s over a Frame-Relay wide area network from a single HP-3000. Note the "NO BRIDGE 1 ACQUIRE". This is critical to prevent flooding the routers and network with bridged traffic. The MAC address from the HP-3000 is forwarded from interface to interface on each router hop to the DTC, and the MAC address of the DTC is forwarded along each hop from the remote site back to the HP-3000. The DTC's can be downloaded and managed from the Host based NMMGR on the HP-3000. The download can take a while depending on the bandwidth, but once the download is done, the throughput performance was more than adequate. Eucaristo, Tom Genute Phone: (212) 437-1744 Kara wrote: Do the Cisco routers work for dumb terminals? We are looking for a cost-effective way to remove bridging from our network. Currently, we have dtcs at remote locations with a dtc manager centrally located which allows dumb terminals to connect to any of our MPE or Unix systems. Some options we've considered were host-based dtc management or terminal servers. I was told that the only other option was to locate dtc managers at each site. Then the bridging would only be on the segment between the dtc manager and the dtc's, not on the whole network. It's not currently a hot issue, but will again soon, I'm sure. Ideas? Kara Strunk ------------------Reply separator---------------------- I've replied privately to 2 other similar messages over the past couple of weeks. This time I decided to post it to the list for anyone else who may also benefit from it. Kara, You have most everything you need already in place. The only remaining task is to configure bridging on the Cisco router(s). Basically what you need to do is configure transparent bridging on each router that needs to bridge packets. This alone will bridge your remote DTCs to the central site. However, you may then experience some performance problems. To avoid this, create a MAC address list on both the central router and the remote router(s). The remote router's MAC address list should permit forwarding of packets to and from the DTC (MAC address) on the LAN (Ethernet) port of the Cisco router. It should also permit forwarding of packets to and from specific server MAC addresses on the WAN (Serial) interface. That is - the HP3000(s) and the DTC/Manager server at your central site. On the remote router configure "NO BRIDGE n ACQUIRE" (n is the bridge environment number you assign to the bridge group) - otherwise the router will acquire MAC addresses for every device on every network known to the router and forward their packets over all network connections. If you do a "show bridge <interface_name>", you will probably see screen after screen of MAC addresses in the table. After setting up the MAC table, only packets to/from the hosts defined in the MAC list will be forwarded - all others will be discarded. On the central router configure a MAC address table in much the same way. If you have multiple WAN interfaces or use subinterfaces, create a MAC list entry or each of these - pointing to the MAC address of the remote LAN's DTC. Likewise, create an entry for each of the bridged services on the central LAN connection. If you have multiple remote sites, you should configure those sites before implementing these changes on your central router. After everything is configured on the central router enter config mode and do a "NO BRIDGE n ACQUIRE". Below is an example of one of our remote Cisco router configs. Note - we use separate Frame Relay PVC's for IP and Bridging. However, this should work just as well on a shared IP/Bridged PVC: ----------------------------------------- ! version 11.2 service timestamps debug datetime msec localtime service timestamps log datetime msec localtime service password-encryption service udp-small-servers service tcp-small-servers ! hostname gf_router ! enable secret 5 xxxxxxxxxxxxxxxx enable password 7 xxxxxxxxxxxxx ! ip hp-host fcpl.fairfax.lib nnn.nnn.nnn.nnn ip hp-host fcpl nnn.nnn.nnn.nnn ip domain-name your.domain.name ip name-server your.name.server isdn switch-type basic-dms100 clock timezone EST -5 clock summer-time EDT recurring ! interface Ethernet0 description Great Falls Ethernet LAN ip address nnn.nnn.nnn.nnn nnn.nnn.nnn.nnn loopback priority-group 1 bridge-group 1 (Turns on bridging for this interface) ! interface Serial0 description GF Circuit # 36.QGDQ.746758 to CH/Tech. Ops. no ip address encapsulation frame-relay priority-group 1 frame-relay lmi-type ansi ! interface Serial0.1 point-to-point description IP PVC mapped to CH/Tech. Ops DLCI 535 ip address nnn.nnn.nnn.nnn nnn.nnn.nnn.nnn frame-relay interface-dlci 337 ! interface Serial0.2 point-to-point description IEEE STP PVC mapped to CH/Tech.Ops. DLCI 536 frame-relay interface-dlci 338 bridge-group 1 (Turns on bridging for this interface) ! interface Serial1 description Spare Serial Interface no ip address shutdown ! interface BRI0 no ip address shutdown ! router eigrp 3333 passive-interface Ethernet0 network nnn.nnn.nnn.nnn network nnn.nnn.nnn.nnn no auto-summary ! no ip classless priority-list 1 protocol bridge high snmp-server community public RO snmp-server community fcpl RW snmp-server community fcpl1 RW snmp-server host nnn.nnn.nnn.nnn host_name bridge 1 protocol ieee (Defines the bridge environment) no bridge 1 acquire (The Cisco default is to "acquire") bridge 1 address 0800.0970.1b3b forward Ethernet0 (remote DTC) bridge 1 address 0800.09db.e15f forward Serial0.2 338 (central HP3000) bridge 1 address 0800.0998.38df forward Serial0.2 338 (central HP3000) bridge 1 address 0800.09c0.ca22 forward Serial0.2 338 (central DTC/Mgr.) ! line con 0 timeout 0 0 password 7 xxxxxxxxxxxx line aux 0 transport input all rxspeed 2400 txspeed 2400 flowcontrol hardware line vty 0 4 password 7 xxxxxxxxxxxxx login ! end ___________________________________________ Steve Barrett Steven P. Barrett [log in to unmask] <mailto:[log in to unmask]> Systems Analyst Fairfax County Public Library (703) 222-3132 - Voice Technical Operations Center (703) 222-3135 - FAX 4000 Stringfellow Rd. Chantilly, VA 20151 --- The opinions expressed here are mine alone . --- If God had meant for us to have distributed systems, he would have put little brains in our hands and in our fingers. (Unknown Author)