[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference netcad::hub_mgnt

Title:	DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:	Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:	NETCAD::COLELLADT

Created:	Wed Nov 13 1991
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	4455
Total number of notes:	16761

1040.0. "DECbridge90 Forwarding Database" by EWBV06::KASAHARA () Mon May 30 1994 06:40

Hi all,

I have a problem regarding TCP/IP communication on DECbridge 90.

   Configuration:
                          on DEChub 90
             +----+      +-----+-----+
             |VAX |      |DB90 |DR90T+------------+---------[]
	     +-+--+      +--+--+-----+        +---+-----------+
        []-----+------------+----[]           |SUN workstation|
                                              +---------------+
		
	VAX  : UCX V2.0
        DB90 : DECbridge 90 Firmware V3.1
	DR90T: DECrepeater 90T 
	SUN  : SunOS V4.1.1


   Problem Scenario:

   I attempted to connect from VAX to Sun workstation with using ucx 
   telnet command. If VAX(UCX) does not have a ARP entry for Sun workstation,
   it works fine. After a few minutes, If I try this operation again with 
   using this ARP entry, it does NOT work.

   Supplement:

   In case of no ARP entry, VAX(UCX) transmits ARP request packet on Ethernet
   broadcast, and the target-host(SUN) sends back ARP reply to VAX.
   In this time, DB90 can have each address on the Forwarding Database, and
   this connection is established correctly.

   Question:

   When DB90 doesn't have the address of Sun workstation on Forwarding
   database, Is the packet sending to Sun discarded on DB90?
   In other words, Does DB90 forward the unknown destination packet to 
   any segument, when DB90 doesn't have any forwarding database entry?

Thanks in advance.
Yoshifumi.

T.R	Title	User	Personal Name	Date	Lines
1040.1	Known feature (problem).	CGOS01::DMARLOWE	Have you been HUBbed lately?	`Mon May 30 1994 11:10`	9
	This has been discussed many times. The DB 90 will NOT forward unknown addresses through to the work group side. It will only forward if the address is in the address table. This means that all nodes in the workgroup side must broadcast at least once in the AGE OUT timer. DECNET and LAT do this but TCP doesn't. Check other notes for some ideas. dave
1040.2	More question	EWB977::HOSOI	Nobuyuki Hosoi,TNSG/CSC/MCS-Japan	`Tue May 31 1994 05:31`	228
	Hi, Dave > forward if the address is in the address table. This means that > all nodes in the workgroup side must broadcast at least once in > the AGE OUT timer. DECNET and LAT do this but TCP doesn't. > Check other notes for some ideas. Thank you for your information. May I ask more question? I try to use "flood mode" feature for workaround. (execute next command from DECbridge 90 console.) DECbridge> define bridge age 0 DECbridge> define bridge flood ENABLE DECbridge> define bridge Spanning_tree ENABLE After DECbridge 90 restart, The bridge status became disabled. The status of port 1 was disabled and port 2 was forwarding. (See appendix 1 for more detail.) The "SET ALL" command(from DECbridge 90's console) improved this situation. (See appendix 2 for more detail.) Q1: Is this a problem or restriction? Next, I set up DECbridge 90's characteristics as following. DECbridge> define bridge age 0 DECbridge> define bridge Flood ENABLE DECbridge> define bridge Spanning_tree DISABLE So, There is no-problem in this combination. Q2: Is the privious combination illegal? (The privious combination means "Flood ENABLE" and "Spanning tree ENABLE) Best regards, Nobuyuki APPENDIX 1 : $ set h/mop db90 %CCR-I-CONNEST, connection established to remote system 08-00-2B-28-D4-88 Press CTRL/\ to disconnect, CTRL/] to send break DEWGB V2.1 08-00-2B-28-D4-88 �1991,92 Digital Equip Corp FPROM V3.1 �1991,93 Digital Equip Corp 5-APR-93 DECbridge>LIST BRIDGE Maximum address entry age: 02 seconds. Preforwarding and blocking delay: 122.56 seconds. Hub mgmt enable: 1 Spanning tree enable: 1 User flood mode enable: 1 Restart the DECbridge 90 (Power off/on) $ set h/mop db90 %CCR-I-CONNEST, connection established to remote system 08-00-2B-28-D4-88 Press CTRL/\ to disconnect, CTRL/] to send break DEWGB V2.1 08-00-2B-28-D4-88 �1991,92 Digital Equip Corp FPROM V3.1 �1991,93 Digital Equip Corp 5-APR-93 DECbridge> SHOW BRIDGE DEWGB V2.1 08-00-2B-28-D4-88 �1991,92 Digital Equip Corp FPROM V3.1 �1991,93 Digital Equip Corp 5-APR-93 Bridge states: Console owner: AA-00-04-00-D3-FF Uptime: 24.20 seconds Bridge state: 1A Work group size: 0 Hub mgmt enable: 1 Spanning tree enable: 1 Flash ROM erasures: 258 Address lifetime: 02 sec. User flood mode enable: 1 Event counters: Sys buffer unavail. errors: 0 WG size exceeded errors: 0 Spanning tree parameters: Bridge id: FF-FF-08-00-2B-28-D4-88 Root port: 0 Designated_root: FF-FF-08-00-2B-28-D4-88 Root path cost: 0 ^^^^^^^^^^^^^^^^^^^^^^^ ^^^ The DECbridge 90 did'not receive bridge hello message . * But Designated Bridge(00-04-08-00-7C-00-4F-2B) exist on this LAN. Current Forward delay: 15, Hello interval: 1, Listen time: 15 Def. Forward delay: 15, Hello interval: 1, Listen time: 15 Topology change flag: 0 Topology change timer: 30 Bad hello limit:15 Bad hello reset interval: 5 Epoch_mode: 3 Epoch1 who: 00-00-00-00-00-00 Mode changes: 0 Epoch 1 poll time: 18 seconds Epoch 1 response time: 15 seconds DECbridge> SHOW PORT 1 Port 1 (Backbone side) Disabled state: 1 Broken state: 0 Event counters: Port address: 08-00-2B-28-D4-88 Frames received: 3,035 Frames relayed to work group: 0 Received block check error: 0 Received framing error: 0 Received frame too long: 0 Frames sent: 194 Frames sent, initially deferred:1 Frames sent, single collision: 0 Frames sent, multiple coll.: 0 Unsent, excessive collisions: 0 Unsent, carrier check failed: 0 Unsent, remote failure to defer:0 Unsent, lifetime exceeded: 0 Spanning tree parameters: State: 0 Path cost: 10 Desig. root: FF-FF-08-00-2B-28-D4-88 Desig. bridge: FF-FF-08-00-2B-28-D4-88 Desig. port: 00-01 Desig. cost: 0 Bad_hellos: 0 Bad hello limitexceeded: 0 Topology change ack: 0 DECbridge> SHOW PORT 2 Port 2 (Work group side) Disabled state: 0 Broken state: 0 Event counters: Port address: 08-00-2B-68-D4-88 Frames received: 0 Frames relayed to backbone: 0 Received block check error: 0 Received framing error: 0 Received frame too long: 0 Frames sent: 51 Frames sent, initially deferred:0 Frames sent, single collision: 0 Frames sent, multiple coll.: 0 Unsent, excessive collisions: 0 Unsent, carrier check failed: 0 Unsent, remote failure to defer:0 Unsent, lifetime exceeded: 0 Spanning tree parameters: State: 3 Path cost: 10 Desig. root: FF-FF-08-00-2B-28-D4-88 Desig. bridge: FF-FF-08-00-2B-28-D4-88 Desig. port: 00-02 Desig. cost: 0 Bad_hellos: 0 Bad hello limit exceeded: 0 Topology change ack: 0 APPENDIX 2 : After SET ALL command DECbridge> SET ALL DECbridge> SHOW BRIDGE DEWGB V2.1 08-00-2B-28-D4-88 �1991,92 Digital Equip Corp FPROM V3.1 �1991,93 Digital Equip Corp 5-APR-93 Bridge states: Console owner: AA-00-04-00-D3-FF Uptime: 98.96 seconds Bridge state: 1F Work group size: 0 Hub mgmt enable: 1 Spanning tree enable: 1 Flash ROM erasures: 258 Address lifetime: 02 sec. User flood mode enable: 1 Event counters: Sys buffer unavail. errors: 0 WG size exceeded errors: 0 Spanning tree parameters: Bridge id: FF-FF-08-00-2B-28-D4-88 Root port: 1 Designated_root: 00-04-08-00-7C-00-4F-2B Root path cost: 257 ^^^^^^^^^^^^^^^^^^^^^^^ ^^^ DECbridge 90 receive bridge hello from Designated Bridge. Current Forward delay: 15, Hello interval: 1, Listen time: 15 Def. Forward delay: 15, Hello interval: 1, Listen time: 15 Topology change flag: 1 Topology change timer: 30 Bad hello limit: 15 Bad hello reset interval: 5 Epoch_mode: 1 Epoch1 who: 00-00-00-00-00-00 Mode changes: 1 Epoch 1 poll time: 18 seconds Epoch 1 response time: 15 seconds DECbridge> SHOW PORT 1 Port 1 (Backbone side) Disabled state: 0 Broken state: 0 Event counters: Port address: 08-00-2B-28-D4-88 Frames received: 8,227 Frames relayed to work group: 1,044 Received block check error: 0 Received framing error: 0 Received frame too long: 0 Frames sent: 701 Frames sent, initially deferred:6 Frames sent, single collision: 0 Frames sent, multiple coll.: 0 Unsent, excessive collisions: 0 Unsent, carrier check failed: 0 Unsent, remote failure to defer:0 Unsent, lifetimeexceeded: 0 Spanning tree parameters: State: 3 Path cost: 10 Desig. root: 00-04-08-00-7C-00-4F-2B Desig. bridge: 00-FA-08-00-2B-20-55-90 Desig. port: 00-02 Desig. cost: 247 Bad_hellos: 0 Bad hello limit exceeded: 0 Topology change ack: 0 DECbridge> SHOW PORT 2 Port 2 (Work group side) Disabled state: 0 Broken state: 0 Event counters: Port address: 08-00-2B-68-D4-88 Frames received: 0 Frames relayed to backbone: 0 Received block check error: 0 Received framing error: 0 Received frame too long: 0 Frames sent: 1,842 Frames sent, initially deferred:0 Frames sent, single collision: 0 Frames sent, multiple coll.: 0 Unsent, excessive collisions: 0 Unsent, carrier check failed: 0 Unsent, remote failure to defer:0 Unsent, lifetime exceeded: 0 Spanning tree parameters: State: 3 Path cost: 10 Desig. root: 00-04-08-00-7C-00-4F-2B Desig. bridge: FF-FF-08-00-2B-28-D4-88 Desig. port: 00-02 Desig. cost: 257 Bad_hellos: 0 Bad hello limit exceeded: 0 Topology change ack: 0
1040.3		4678::SLAWRENCE		`Mon Jun 06 1994 10:19`	14
	I don't recommend fooling with the Bridge to try to fix this; other than perhaps setting the bridge age to 0. It is much easier to configure the Sun workstation to do something (anything) that causes it to send a packet now and then. There are lots of choices for this; among them: Configure NTP (preferably client, since Sun clocks aren't that good). Turn on one or more of the BSD broadcast-based services: rwho, rdate, ruptime As long as it isn't silent for too long, you'll be fine.
1040.4	reply to 1040.2	NPSS::RAUHALA		`Thu Oct 13 1994 17:28`	9
	The problem with "DEFINE BRIDGE FLOOD ENABLE" is that on power-up port 1 became disabled. This causes forwarding to stop. There was also a problem with the "SET ALL" command. Sometimes it would cause port 1 to become disabled. The fixes for these problems are in the new image: NPSS::PUBLIC$DSK:[INTERCHANGE]DEWGB_V39.TSK