An S5700 Fails to Communicate with a Server with Dual Network Adapters Equipped

Publication Date:  2015-10-13 Views:  961 Downloads:  0
Issue Description
As shown in Figure 6-1, an S5700 is connected to an HP server through an Eth-Trunk in manual load balance mode. The HP server has dual network adapters and uses a virtual MAC address. The S5700 cannot ping the HP server.

Figure 6-1 A server with dual network adapters is connected to an S5700

Handling Process
Check the configuration of the HP server. The output information shows that the dual network adapters of the HP server work in 802.3ad mode; therefore, the connected switch should use the LACP mode. However, the S5700 is using the manual load balance mode for link aggregation.

Change the link aggregation mode on the S5700 to LACP.

interface Eth-Trunk1
mode lacp-static
#
interface GigabitEthernet0/0/1
eth-trunk 1
bpdu enable
#
interface GigabitEthernet0/0/2
eth-trunk 1
bpdu enable
Root Cause
The HP server uses a bundle of dual network adapters to improve reliability. The link aggregation mode on the S5700 must match the working mode of the network adapters. The dual network adapters of the HP server work in 802.3ad mode, which is the standard for link aggregation. Therefore, the S5700 must use the LACP mode.
Suggestions
For the mappings between the link aggregation modes on the server and switch, see Figure 6-1.

Table 6-1 Mappings between the link aggregation modes on server and switch

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