@mike-davis said in MTU size > 1500:
So I did this test:
C:\>ping -f -l 1473 208.73.144.1
Pinging 208.73.144.1 with 1473 bytes of data:
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Ping statistics for 208.73.144.1:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
C:\>ping -f -l 1472 208.73.144.1
Pinging 208.73.144.1 with 1472 bytes of data:
Reply from 208.73.144.1: bytes=1472 time=79ms TTL=244
Reply from 208.73.144.1: bytes=1472 time=79ms TTL=244
Reply from 208.73.144.1: bytes=1472 time=79ms TTL=244
Reply from 208.73.144.1: bytes=1472 time=79ms TTL=244
Ping statistics for 208.73.144.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 79ms, Maximum = 79ms, Average = 79ms
Then I set the MTU on the SonicWall down to 1472 since that was the largest that worked. When I test now, it's 28 bits lower. Is that to be expected, or is something wrong? Should the BLF thing be resolved?
C:\>ping -f 208.73.144.1 -l 1444
Pinging 208.73.144.1 with 1444 bytes of data:
Reply from 208.73.144.1: bytes=1444 time=79ms TTL=244
Reply from 208.73.144.1: bytes=1444 time=79ms TTL=244
Reply from 208.73.144.1: bytes=1444 time=79ms TTL=244
Reply from 208.73.144.1: bytes=1444 time=79ms TTL=244
Ping statistics for 208.73.144.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 79ms, Maximum = 79ms, Average = 79ms
C:\>ping -f 208.73.144.1 -l 1445
Pinging 208.73.144.1 with 1445 bytes of data:
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Ping statistics for 208.73.144.1:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
What you are doing thus far is common with adsl and firewalls.
What is the BLF issue? What phone and platform?