BigIron RX Series Configuration Guide
365
53-1001810-01
Convergence in a simple topology
13
Next, Switch 1 is powered up (
Figure 54
).
FIGURE 54
Simple Layer 2 topology
The point-to-point connections between the three bridges are as follows:
•
Port2/Switch 1 and Port2/Switch 2
•
Port4/Switch 1 and Port4/Switch 3
•
Port3/Switch 2 and Port3/Switch 3
Ports 3 and 5 on Switch 1 are physically connected together.
At start up, the ports on Switch 1 assume Designated port roles, which are in discarding state. They
begin sending RST BPDUs with proposal flags to move into a forwarding state.
When Port4/Switch 3 receives these RST BPDUs RSTP algorithm determines that they are better
than the RST BPDUs that were previously received on Port3/Switch 3. Port4/Switch 3 is now
selected as Root port. This new assignment signals Port3/Switch 3 to begin entering the discarding
state and to assume an Alternate port role. As it goes through the transition, Port3/Switch 3
negotiates a new role and state with its peer port, Port3/Switch 2.
Port4/Switch 3 sends an RST BPDU with an agreed flag to Port4/Switch 1. Both ports go into
forwarding states.
Port2/Switch 2 receives an RST BPDU. The RSTP algorithm determines that these RST BPDUs that
are superior to any that any port on Switch 2 can transmit; therefore, Port2/Switch 2 assumes the
role of a Root port.
The new Root port then signals all ports on the bridge to start synchronization. Since none of the
ports are Edge ports, they all enter the discarding state and assume the role of Designated ports.
Port3/Switch 2, which previously had a Designated role with a forwarding state, starts the
discarding state. They also negotiate port roles and states with their peer ports. Port3/Switch 2
also sends an RST BPU to Port3/Switch 3 with a proposal flag to request permission go into a
forwarding state.
Switch 2
Switch 3
Switch 1
Port2
Designated
port
Port4
Designated port
Port3
Designated
port
Port3
Designated
port
Port5
Backup port
Port3
Alternate
port
Port2
Root port
Port4
Root port
Bridge priority = 1500
Bridge priority = 2000
Bridge priority = 1000
Содержание Brocade DCX
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Страница 318: ...246 BigIron RX Series Configuration Guide 53 1001810 01 Deploying a LAG 8 ...
Страница 418: ...346 BigIron RX Series Configuration Guide 53 1001810 01 SuperSpan 12 ...
Страница 482: ...410 BigIron RX Series Configuration Guide 53 1001810 01 MRP CLI example 14 ...
Страница 506: ...434 BigIron RX Series Configuration Guide 53 1001810 01 Displaying VSRP information 15 ...
Страница 566: ...494 BigIron RX Series Configuration Guide 53 1001810 01 QoS for the oversubscribed 16 x 10GE modules 18 ...
Страница 582: ...510 BigIron RX Series Configuration Guide 53 1001810 01 Viewing Layer 2 ACLs 20 ...
Страница 634: ...562 BigIron RX Series Configuration Guide 53 1001810 01 Troubleshooting ACLs 21 ...
Страница 642: ...570 BigIron RX Series Configuration Guide 53 1001810 01 Trunk formation 22 ...
Страница 746: ...674 BigIron RX Series Configuration Guide 53 1001810 01 Displaying RIP filters 24 ...
Страница 808: ...736 BigIron RX Series Configuration Guide 53 1001810 01 Displaying OSPF information 25 ...
Страница 926: ...854 BigIron RX Series Configuration Guide 53 1001810 01 Generalized TTL security mechanism support 26 ...
Страница 938: ...866 BigIron RX Series Configuration Guide 53 1001810 01 Displaying MBGP information 27 ...
Страница 950: ...878 BigIron RX Series Configuration Guide 53 1001810 01 Using secure copy 28 ...
Страница 988: ...916 BigIron RX Series Configuration Guide 53 1001810 01 Clearing IS IS information 29 ...
Страница 998: ...926 BigIron RX Series Configuration Guide 53 1001810 01 Configuring BFD for the specified protocol 30 ...
Страница 1014: ...942 BigIron RX Series Configuration Guide 53 1001810 01 Displaying multi device port authentication information 31 ...
Страница 1054: ...982 BigIron RX Series Configuration Guide 53 1001810 01 Sample 802 1x configurations 33 ...
Страница 1072: ...1000 BigIron RX Series Configuration Guide 53 1001810 01 IP source guard 35 Syntax show ip source guard ethernet port num ...
Страница 1108: ...1036 BigIron RX Series Configuration Guide 53 1001810 01 sFlow 39 ...
Страница 1190: ...1118 BigIron RX Series Configuration Guide 53 1001810 01 Displaying RIPng information 44 ...
Страница 1270: ...1198 BigIron RX Series Configuration Guide 53 1001810 01 Displaying ACLs 47 ...
Страница 1310: ...1238 BigIron RX Series Configuration Guide 53 1001810 01 Displaying OSPFv3 information 48 ...
Страница 1382: ...1310 BigIron RX Series Configuration Guide 53 1001810 01 Commands That Require a Reload D ...
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