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>> >> Maybe run a ping to a destination which you are having problems |
| 2 |
>> >> with, then reproduce the problem (with the network idle |
| 3 |
>> >> otherwise). You should see ping packets dropped only then. |
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>> >> |
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>> >> You can also ping with increasing packet sizes (see ping --help) |
| 6 |
>> >> and see when the packet becomes too big for path MTU. But instead |
| 7 |
>> >> lowering your MTU then, you should allow icmp-fragmentation-needed |
| 8 |
>> >> come through reliably. Lowering MTU only makes sense to stop |
| 9 |
>> >> overly fragmentation in the first place and optimize for a |
| 10 |
>> >> specific packet path (like traffic through one or multiple VPN |
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>> >> tunnels) where fragmentation would otherwise increase latency a |
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>> >> lot, or where icmp-frag-needed does not correctly work. |
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>> > |
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>> > |
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>> > I'll try pinging today once the issue pops up. |
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>> |
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>> |
| 18 |
>> I'm seeing the issue again as usual but ping response times come back |
| 19 |
>> normal at about 50ms. I'll keep trying. |
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> |
| 21 |
> Not sure if this came after or before switching your router to modem |
| 22 |
> mode... But if it happened before and is solved now, your router really |
| 23 |
> doesn't well with icmp packets or has problems with mss clamping / pmtu. |
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| 26 |
I did not try pinging before switching the device from router to modem. |
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BTW, I read that setting CLAMPMSS=Yes in shorewall.conf is a necessity |
| 29 |
when using PPPoE but my connection is working fine without that |
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setting. Should I set it anyway? |
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- Grant |
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