Cisco Ethernet switch Operations Instructions download pdf (Page 75)

Chapter 5. Cisco Systems IGESM management and user orientation 61

There is one possible exception to this rule: Often during an IGESM’s initial evaluation period,

a simple single VLAN network is set up for test purposes. Scenario 7 in this section discusses

the possibilities and ramifications of this approach.

On a slightly different subject, one question that might be asked is: Why are port g0/15 and

g0/16 hard-coded as trunks if all I want to do is carry untagged data to the Management

Module? Why not hard-code it to a simple Access link and prevent the confusion?

One reason is that the BladeCenter supports a feature known as Serial over LAN (SoL) that

permits a user to Telnet to the Management Module, then connect over a special VLAN,

through the IGESM, and into each individual blade server. Because the SoL VLAN must be

different from the IGESM’s Management VLAN (to isolate the flows), it is necessary to carry

two VLANs over the link between the Management Module and the IGESM when using SoL.

The only way to carry more than a single VLAN on a single physical link and still maintain

isolation of the flows is to use a trunk connection (802.1Q in this case). When using SoL, the

IGESM management traffic will always be on the native VLAN (untagged) while the SoL

VLAN will be some other VLAN (tagged).

5.3.5 Considerations: Using the IGESM uplinks to manage the IGESM

Scenarios 3 through 6 in this section discuss how to utilize the IGESM’s uplinks to provide a

management path to IGESMs in a BladeCenter. Note that

only scenarios 3 and 4 are

recommended in production environments that use the IGESM uplinks for IGESM

management. Scenarios 5 and 6 are being provided simply to show possible issues that

could be encountered when using the IGESM uplink ports to manage the IGESM.

Using the IGESM uplink ports to manage an IGESM requires five basic considerations:

1. Enable management over the IGESM uplinks.

Make sure that External management over all ports on the Management Module is set to

Enabled. This is so the IGESM can respond to ARP requests from its uplink ports for its

management interface VLAN’s IP address.

2. Isolate IGESM management VLAN from any blade server facing ports.

Ensure that the VLAN that is used by the IGESM for management is not used by any of

the blade servers in the BladeCenter chassis. This is necessary to prevent Management

Module proxy issues for the blade servers. This is less of an issue when managing the

IGESM via its own uplinks (as opposed to the Management Module uplink), but it is still

good to follow this rule. (An exception to this rule is shown in scenario 4).

3. Carry the IGESM management VLAN on IGESM uplinks.

Make sure that the VLAN that is used by the IGESM as its management VLAN is carried

on at least one of the uplinks from the IGESM to the upstream switch (or switches). This

may be carried over an Etherchannel bundle and may be carried as part of an 802.1Q

trunk or as a simple

access-type connection.

4. Ensure that the IGESM management VLAN is not the same as the Management Module’s

upstream VLAN.

Make sure that the VLAN that is used by the IGESM on its management VLAN interface is

not the same as the VLAN used by the Management Module’s upstream connection to the

Management Module. Because we are now attempting to manage the IGESM via its own

uplinks, we want to isolate the IGESM management interface VLAN from the VLAN being

used to support the Management Module.

1 ... 74 75 76 ... 266

Comments to this Manuals

No comments

Cisco Ethernet switch Operations Instructions Page 75

Comments to this Manuals

Related products and manuals for Networking Cisco Ethernet switch