LACP for MPLS packets

Question

Hello.

We are using Dell Force10 switch as a transit switch with LACP port channel.
When traffic is going across port channel - traffic is going only in one interface.

What type of hash algorithm we need to set?
Is this config will solve our ptoblem?

kiev_gdr50_dell(conf)#hash-algorithm ?
ecmp Options for ECMP hashing
lag Options for Lag hashing
seed Hash Algorithm seed for ECMP, LAG
kiev_gdr50_dell(conf)#hash-algorithm lag ?
crc16 CRC16_BISYNC - 16 bit CRC16-bisync polynomial
crc16cc CRC16_CCITT - 16 bit CRC16 using CRC16-CCITT polynomial
crc32LSB CRC32_LOWER - LSB 16 bits of computed CRC32(default)
crc32MSB CRC32_UPPER - MSB 16 bits of computed CRC32
xor1 CRC16_BISYNC_AND_XOR1 - Upper 8 bits of CRC16-BISYNC and lower 8 bits of xor1
xor2 CRC16_BISYNC_AND_XOR2 - Upper 8 bits of CRC16-BISYNC and lower 8 bits of xor2
xor4 CRC16_BISYNC_AND_XOR4 - Upper 8 bits of CRC16-BISYNC and lower 8 bits of xor4
xor8 CRC16_BISYNC_AND_XOR8 - Upper 8 bits of CRC16-BISYNC and lower 8 bits of xor8
xor16 CR16 - 16 bit XOR

Dell-DylanJ · Answer

You may find this page a useful resource. It goes into more detail on ECMP.

https://dell.to/38ss9sP

Secondly, where is the the traffic coming from? The reason I ask is because it isn't going to load balance from a single source, if you're using a single test device. If you can share the switch model and firmware, I can look for more targeted information.

AlexLanS · Answer

Hello. I using Dell S4810. They are connected one after another. They are have 16 links to each with LACP. Between them i have one vlan from first switch to last. On this vlan have connected MPLS switch on first and last switch. Scheme like this: MPLS router(172.25.2.18/30) - vlan10(LACP-16 ports) - Dell S4810 - vlan10(LACP-16 ports) - Dell S4810 - vlan10(LACP-16 ports) - Dell S4810 - MPLS router(172.25.2.17/30). MPLS running on this two IP addresses 172.25.2.18 and 172.25.2.17. When traffic is going from MPLS router 1 to MPLS router 2 we see than traffic os going only in one of 16 ports. So balancing not working. Is this possible balance this traffic between LACP on Dell S4810.

DELL-Josh Cr · Answer

Page 907 https://dell.to/2KK5kZE It shows how the hashing works the S4810 can carry MPLS tagging but it doesn’t have full MPLS support for load balancing.

AlexLanS · Answer

So, this is impossible to balance traffic between LACP ports?

Dell-DylanJ · Answer

You might try a static method to see if you can produce a different result. You can find some information about that linked below. I don't know that you can use that to produce the desired effect, but it may be worth investigating.

https://dell.to/3o9h3jf

Networking General

LACP for MPLS packets

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