Destination Host Unreachable

[alexbn71]

Hi, I 've a strange issue since two weeks. There are some trouble in my network routing involving the unRaid NAS. 

From the NAS I can't ping some IPs e from that IPs the ping of NAS it does't work. The message in both direction is always "Destination Host Unreachable". The strange thing is that there is a small amount of IPs that can't ping the NAS and vice versa all others IPs works corerctly.

The only thing I made was to try WireGuard... (now disabled). I don't know if this has changed something in the routing table of the NAS.

 

Someone can help me to understand what's going on? or how to investigate the issue?

 

 

[MAM59]

Do you have by chance enabled "bonding" on two network adapters and connected both ports to  a single switch (I would guess a Fritzbox because of the 178 address?).

 

That is no good idea because the FB is not capable to honor this kind of connection, what happens is, that SOME clients work, OTHERS not. This is because one of the bonding selection criteria is based on the lowest bit of the last byte of the MAC address of the interfaces of the clients. Like "the odd ones go to card 1, the even ones go to card 2".

 

Use this with unsupported hardware involved, you see this "black holes" within you lan.

(Simple solution: disable bonding, pull out one cable)

 

Edited June 23, 2022 by MAM59

[alexbn71]

Yes it's a FritzBox.... could you explain more in detail? how to disable bonding? wich cable should I disconnet?

[MAM59]

if you have TWO (or more) connections from your UNRAID box to the Fritzbox, remove ALL BUT ONE.

 

 

[alexbn71]

Uhmmmm there is only one cable from my unRaid box.... but take a look at this screenshot:

 

[MAM59]

ok, then forget what I said, it does not apply to you (but you may consider to disable bonding in your network setting, its the default, but its dangerous if people dont know how and what it does).

 

[alexbn71]

but I never enabled this feature on my unRaid box... something modified by WireGuard or other installed/tried on the NAS?

 

How can be disabled?

[MAM59]

as I said, its default.

It does not really matter unless you connect more than one cable to the same switch. You can turn it off, but with you current one connection, it wont hurt you.

It was just my GUESS that there could be more than one cable. Then this setting comes into action and may do some harm (but with your current settings it would not harm anything even IF you connect twice. The "fault-tolerance" mode only uses one card and switches over to the other, when the first link fails. They never operate at the same time)

 

To disable it permanently you have to stop the array, go to the network settings and select "NO" for "bonding" on every network card. But, as already said, it is not needed, I had the wrong idea reading you error description, so this is not the solution you are looking for, sorry.

 

[alexbn71]

issue fixed! the culprit was the fritzbox! 🤬

 

the fritzbox memorized the ip of my nas as if it were coming from "wlan" (while it has always been hard wired) ... and in fact from the NAS itself I could not ping only the "vlan" devices but saw only the "lan" ones. I made the fritzbox forget that connection et voila

 

Thank you MAM59... it was useful to have some more knowledge on bonding 👍