Cisco 877 - I am guessing LAN throughput issue

Found the issue

For some reason it doesnt like FastEthernet0 being hardcoded to 100mb full duplex, this interface is the link to my other router which is the TPLink (which handles the FTTC connection).

Set this to auto, and left the rest of the cisco interfaces hard coded to 100mb full duplex

Speed from my VM now getting my normal bandwidth out to the internet, 65mb down and 17mb up

No more CRC errors on that, not sure why it didnt like being hard coded

When you set a device to auto-neg it sends link pulse messages across the link - these basically signal the adjacent interface with it's own status, which enables it to set itself to the same mode.

When you hard-code the speed/duplex on a device, the link pulses containing the speed/duplex information are not sent (because it's hard coded) if the adjacent device is configured for auto - it will fallback to the safest mode capable of connectivity (usually 100/half duplex) because it doesn't know what the adjacent node is set too,

Or something along those lines,
 
Pretty much yeah :) which would cause CRC errors although for some reason I thought I hard coded the TPLINK to 100 full, not been on there in a while.

Anyway bandwidth is awesome again :) next task is to terminate VPN on the Cisco instead of a windows VM, see if it works
 
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