Re: VIOS etherchannel modes

I just had an issue with this, it's not exactly the same but my fix
worked. I had a regular lpar with NIC's in a pri/pri (this was the whole
problem) configuration. Each one of the cables went to each one of our
network cores. In my case this was a no-no beacuse between our network
cores and the etherchannel, heavier traffic would get totally messed up
and the EC didn't know how to distribute the traffic between the
adapters, at which point we'd see a huge network slowdown, user
complaints, etc.

All I ended up doing is recreating the EC to a pri/backup config
(ent0-primary, ent1-backup, ent2-EC) and everything cleared up with no
problems. I'm not sure of your exact configuration or how your network
handles things, but this is my 2 cents. Hope it helps you a little.

Regards,
Darryl

________________________________

From: IBM AIX Discussion List [mailto:aix-l@xxxxxxxxxxxxx] On Behalf Of
Mills, John T
Sent: Wednesday, June 17, 2009 7:52 AM
To: aix-l@xxxxxxxxxxxxx
Subject: VIOS etherchannel modes


I've been having a weird issue with EC aggregation as part of a SEA VIOS
config. We have four wires, two to each VIOS, for a subnet. Those
wires are used to form an aggregate (pri/pri) EC for a backend device
for our SEA. If I 'smitty etherchannel' and cut one of the primaries
out about 60% of the time the whole EC stops working. I disconnected
the SEA from the EC for troubleshooting and the behavior is just odd.
I'm wondering if it's the mode that's causing the wierdness, and, we are
looking at it on the network side as well.

So the question is, does anyone see anything wrong with:

adapter_names ent0,ent3 EtherChannel Adapters
True
alt_addr 0x000000000000 Alternate EtherChannel Address
True
auto_recovery yes Enable automatic recovery after failover
True
backup_adapter NONE Adapter used when whole channel fails
True
hash_mode default Determines how outgoing adapter is chosen
True
mode standard EtherChannel mode of operation
True
netaddr 0 Address to ping
True
noloss_failover yes Enable lossless failover after ping
failure True
num_retries 3 Times to retry ping before failing
True
retry_time 1 Wait time (in seconds) between pings
True
use_alt_addr no Enable Alternate EtherChannel Address
True
use_jumbo_frame no Enable Gigabit Ethernet Jumbo Frames
True

# lsattr -El ent0
alt_addr 0x000000000000 Alternate ethernet address
True
busintr 131237 Bus interrupt level
False
busmem 0xf0120000 Bus memory address
False
chksum_offload no Enable hardware transmit and receive
checksum True
compat_mode no Gigabit Backward compatability
True
copy_bytes 2048 Copy packet if this many or less bytes
True
delay_open no Enable delay of open until link state is
known True
failback yes Enable auto failback to primary
True
failback_delay 15 Failback to primary delay timer
True
failover disable Enable failover mode
True
flow_ctrl yes Enable Transmit and Receive Flow Control
True
intr_priority 3 Interrupt priority
False
intr_rate 10000 Max rate of interrupts generated by
adapter True
jumbo_frames no Transmit jumbo frames
True
large_send yes Enable hardware TX TCP resegmentation
True
media_speed Auto_Negotiation Media speed
True
rom_mem 0xf00c0000 ROM memory address
False
rx_hog 1000 Max rcv buffers processed per rcv
interrupt True
rxbuf_pool_sz 2048 Rcv buffer pool, make 2X rxdesc_que_sz
True
rxdesc_que_sz 1024 Rcv descriptor queue size
True
slih_hog 10 Max Interrupt events processed per
interrupt True
tx_que_sz 8192 Software transmit queue size
True
txdesc_que_sz 512 TX descriptor queue size
True
use_alt_addr no Enable alternate ethernet address
True

# lsattr -El ent3
alt_addr 0x000000000000 Alternate ethernet address
True
busintr 196696 Bus interrupt level
False
busmem 0xc0100000 Bus memory address
False
chksum_offload no Enable hardware transmit and receive
checksum True
compat_mode no Gigabit Backward compatability
True
copy_bytes 2048 Copy packet if this many or less bytes
True
delay_open no Enable delay of open until link state is
known True
failback yes Enable auto failback to primary
True
failback_delay 15 Failback to primary delay timer
True
failover disable Enable failover mode
True
flow_ctrl yes Enable Transmit and Receive Flow Control
True
intr_priority 3 Interrupt priority
False
intr_rate 10000 Max rate of interrupts generated by
adapter True
jumbo_frames no Transmit jumbo frames
True
large_send yes Enable hardware TX TCP resegmentation
True
media_speed Auto_Negotiation Media speed
True
rom_mem 0xc0040000 ROM memory address
False
rx_hog 1000 Max rcv buffers processed per rcv
interrupt True
rxbuf_pool_sz 2048 Rcv buffer pool, make 2X rxdesc_que_sz
True
rxdesc_que_sz 1024 Rcv descriptor queue size
True
slih_hog 10 Max Interrupt events processed per
interrupt True
tx_que_sz 8192 Software transmit queue size
True
txdesc_que_sz 512 TX descriptor queue size
True
use_alt_addr no Enable alternate ethernet address
True


John T. Mills

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