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Bridge node default parameters, Bridge node default parameters -4 – Cabletron Systems 1800 User Manual

Page 256

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16-4

SmartSwitch 1800 4. 0 User G uide, Rev 01

Bridge Node Default Parameters

1

To assure correct operation of the spanning tree algorithm, follow these rules:

a.

Bri dge Max Age

must be less than or equal to twice the value of {

Bridge Forw ard

Delay

minus 1 second}.

b.

Bri dge Max Age

must be greater than or equal to twice the value of {

Bridge Hello

Ti me

plus 1 second}.

2

This parameter is irrelevant on a a Token Ring SmartSwitch 1800.

Bridge Enabled

enables bridging in the node, implementing the spanning tree algorithm.

If Bridging is disabled, all Bridge ports on the node will go into

Forwarding

state (described under "

Bridge Port Status

" on page 20-22). No BPDUs (see

Bridge Hello Time

below) will flow. No data will be bridged except termi-

nated LLC2 traffic.

Bridge Hello Time

is the frequency with which all bridges on the network will send "Hello" messages
(also called BPDUs, or Bridge Protocol Data Units) to adjacent bridges (the next ones
in all bridge paths) when the local bridge is "Root." Note that a root bridge is the one
with the lowest ID (which contains its Bridge Priority and MAC address) on the
network.

Bridge Max Age

determines how long Hello messages will remain valid when the local bridge is root
(described under "

Bridge Hello Time

").

Bridge Forward Delay

is the time the bridge will wait after entering

Listening

state before entering

Learning

state, or after entering

Learning

state before entering

Forwarding

state This delay is

intended to assure that the tree topology is stable before it is put into use.

The states are described under "

Bridge Port Status

" on page 20-22.

Table 16-1 Bridge Node Default Parameters

Parameter

Valid Values

Default Value

Vi rtual LAN ID

n/a – accept the default

Bridge Enabled

Y/N

Y

Bridge Hello Ti me

1–10

(seconds)

1

2

Bridge Max Age

6–40

(seconds)

1

20

Bridge Forward Delay

4–30

(seconds)

1

15

Bridge Agi ng Ti mer

10–10000000

(seconds)

300

Bridge Priori ty

0–65535

32768

Max Size Bridge For warding Table

128–65535

32768

IP Bridging Enabled

Y/N

N

IPX Bridging Enabled

Y/N

N

SRB ID

0–f

(hex)

0

Defaul t Ethernet Frame Type

2

Type II, 802.3

Type II