Standards Based Redundancy With Ieee 802.1S (Mstp) - HP Bc1500 - BladeSystem - Blade PC Supplementary Manual

Network Considerations
•
You can deploy the HP PC Blade Switch into this scenario without making changes to the default con-
figuration.
•
For Cisco networks running PVST/PVST+, links A, B, and C may use either 802.1q or ISL.encapsula-
tion.
•
IEEE 802.3ad Link Aggregation is not available in this scenario.
•
You can achieve VLAN Load Balancing by reversing the links at the aggregation layer for links E and
F. Optimal load balancing may depend upon the configuration of the rest of the network, and further
optimization may require addition configuration.
•
For large deployments, 802.1w may be a better option because the same type of redundancy can be
achieved with two instead of four uplinks.

Standards based redundancy with IEEE 802.1s (MSTP)

(MSTI 1)
A
(MSTI 2)
0/1
Cisco 2960G
0/2
Aggregation Switch 1
0/21
(MSTI 2)
D
(MSTI 1)
Physical Link Forwarding to Root
Logical Link Forwarding Designated
(Alternate) Blocking
Description
•
VLAN 101 assigned to all odd ports e1 - e39 & e45.
•
VLAN 102 assigned to all even ports e2 - e40 & e43.
This reference design illustrates how the use of IEEE 802.1s has benefits of performance optimization
through VLAN load balancing in addition to redundancy over fewer connections. MSTP is relatively diffi-
cult to implement and manage in large networks. In cases where you want MSTP but it is not currently
deployed, consider using it in an isolated spanning tree region. MSTP is backward-compatible with older
protocols and can co-exist fairly easily. If either link A & C or D were to fail, link E would take over.
Network Considerations
•
When configuring the HP PC Blade Switch for IEEE 802.1s operation, disable the PVST Interop fea-
ture (see "Disabling the spanning tree PVST Interoperability mode" on page
Cisco 6500
1/1 Core Switch 1/2
Root for all MSTIs
(MSTI 2)
(MSTI 1)
C
0/2
(MSTI 2)
(MSTI 2)
HP PC Blade
e43 e45
Switch
VLAN 101 Blade PC Image Management, PXE, DHCP,
VLAN 102 Remote Access Devices, HP SAM, HP SIM,
Network Storage, DHCP, DNS, Active Directory
(MSTI 1)
B
0/1
Cisco 2960G
Aggregation Switch 2
0/21
E
(MSTI 1)
17).
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