Hello Noggers,

I have a handful of customers with SQL replication issues over 2 separate 
transit links between Sydney and Melbourne.

Looking to see if anyone here has experienced something similar or could 
potentially shed some light, perhaps more on my carrier configuration and 
traffic preferencing.

We have 2x 10GBps interfaces in 2 separate datacentres for transit across 2 
carriers. This link carries SQL replication.

It appears when we are using 1 carrier link, everything seems fine and traffic 
replicates normally.

However, when we balance between 2 carriers, into the same networks, we start 
seeing issues.

Connections are working, I can telnet, ICMP, etc, however when we start sending 
large packets we see semaphore timeout errors.

To me it points to TCPOffload, however that's all disabled and I can see no 
incorrect packets, etc at both sides.

I have even tried routing the SQL traffic over a different network within the 
same BGP sessions, which works for a while, then eventually starts barfing with 
semaphore timeout issues.

My question is with traffic preferencing, is there anything special I need to 
do when using multiple carriers at the same time for the same networks ?

Happy to hear input and suggestions, off list would be better. I am happy to 
publish what steps were taken.

Many thanks

Darren.
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