Losing WAN connection intermittently

JKnott

One would think that an Ethernet negotiation issue would cause a solid problem, not intermittent. Is there something triggering a disconnect/reconnect? Does the link show down? Also, an intermittent failure shouldn't cause DHCP problems, unless it's long enough for the lease to expire.

JKnott

@comatose_tortoise said in Losing WAN connection intermittently:

Why does pfsense first make DHCPREQUEST to one address, but after a while changes to another?

Do you have a packet capture of the full DHCP sequence?

comatose_tortoise

Ok, so now I changed the NIC for my WAN to one I know for sure is an Intel NIC.

@JKnott said in Losing WAN connection intermittently:

@comatose_tortoise said in Losing WAN connection intermittently:

Why does pfsense first make DHCPREQUEST to one address, but after a while changes to another?

Do you have a packet capture of the full DHCP sequence?

Nope, never done that. I'll try to look into it. But I guess I would need to do it at the exact moment the error occurs? Could be problematic due to the intermittent behavior.

Raffi_

I didn't see this mentioned or suggested yet, so I'll be that guy... you did check the cable between pfSense and the modem? If you have no way of checking it, replace it with a known good cable.

JKnott

@comatose_tortoise

That depends on how you do it. If you use Packet Capture, it would be difficult to catch the first half, though you might be able to if you do a release/renew. The other way is to use a data tap, as I mentioned above, then reboot pfSense to get the initial sequence and as many renews as you want. One advantage of this method, using Wireshark, is you can watch what's happening, without stopping the capture. On the negative side, if it really is a NIC negotiation issue, this might mask it.

DaddyGo

@JKnott said in Losing WAN connection intermittently:

Is there something triggering a disconnect/reconnect?

Who knows deeply the Realtek’s inner world?
The fact is, causes intermittent problems as we are already past this examination and I have read about similar problems in on the other forums.

What do you think of a periodic heat run?
(since it starts with a significant packet loss and not basically with dhcp problem)

something more came to mind because the ISP is not a god:

our other typical case is with Telecom (HU) ISP DOCSIS Cisco CMTS and edgeQAM, using the DHCP allocation method...

the problem is caused by the tightly configured Cisco IOS - Prerequisites for Cable DHCP Leasequery + DHCP MAC Address Exclusion List

the error phenomenon is very similar to the OP s issue

BTW:
-Raisecom replaced the ONT ethernet controller with i211 and all problems went away.

serbus

@comatose_tortoise said in Losing WAN connection intermittently:

After this the gateway goes up and functionality is restored. As I said in the thread start, if I manually release and renew IP on WAN when I notice that I've lost internet connection, it does this last part immediately instead of waiting a long time before asking 255.255.255.255.
Any ideas on why this is? If I could just make renew IP on 255.255.255.255 as soon as WAN gateway goes down, the problem would be, if not solved, radically less severe.

Hello!

Are the 10.x.x.x DHCP servers relays? Maybe they wont accept unicast dhcp request and require broadcasts?

https://forum.netgate.com/topic/112869/dhclient-on-wan-occasionally-fails-to-renew-lease-with-cable-isp

https://social.technet.microsoft.com/Forums/windows/en-US/69a3a8f6-8199-4f24-8d4a-a4b5a083176b/why-cant-windows-7-be-forced-to-use-dhcp-broadcast-lease-renewal

John

DaddyGo

@serbus said in Losing WAN connection intermittently:

Maybe they wont accept unicast dhcp request and require broadcasts?

the problem is only intermittent, so it is not relevant

JKnott

@DaddyGo said in Losing WAN connection intermittently:

What do you think of a periodic heat run?

That could be a possibility. I've seen stuff fail when it gets warm. Many years ago, I learned about some stuff called "Freeze Mist", which was handy for locating thermal problems. It was also useful for putting frost on a penny.

Raffi_

@JKnott said in Losing WAN connection intermittently:

@DaddyGo said in Losing WAN connection intermittently:

What do you think of a periodic heat run?

That could be a possibility. I've seen stuff fail when it gets warm. Many years ago, I learned about some stuff called "Freeze Mist", which was handy for locating thermal problems. It was also useful for putting frost on a penny.

A can of compressed air held upside down does the same thing. I think the "freeze mist" and compressed air are the same product with the can and labels flipped :)

DaddyGo

@Raffi_ said in Losing WAN connection intermittently:

A can of compressed air held upside down does the same thing.

óóóó, the blessed physics and the expanding gases