Link auto-negotiate not working on port 9-11 on XGS1250-12 - V2.00(ABWE.1)C0 (Februari 2025)

sjanssen15

Hi,

I have the following issue with auto-negotiate on ports 9 - 11. They always go to 100M, doesn't matter if I try it with my Realtek 2.5Gbe or Intel 1Gbe NIC, they always go to 100M on these ports. I got the 2.5Gbe NIC working when setting port 9 to 2.5G statically and statically on the PC. But after 5 minutes of working correctly, the switch seems to crash and the link goes down.

The link on all other ports work fine. Ports 1 - 8 auto-negotiate correctly. I use the same cable and PC to test these other ports. Port 12 also links correctly at 10Gbit.

I'm running the latest firmware and this bug has been an issue for me in the last 2 years. I hoped the latest update would fix this issue. On this forum and online I saw more people with the exact same problem.

Zyxel_Melen

Hi @sjanssen15,

1. So all your tests are using the same cable, correct?
2. Since you mentioned that fixing the 2.5G link speed can make the link up for 5 minutes, could you use another cable to test?
3. Could you use the same cable to connect ports 9-11 as a loop to check the link status?
4. I checked my XGS1250-12 with 2.5G NIC, and ports 9-11 are both able to link to 2.5G. Could you share the S/N of your XGS1250-12?

Thanks~

Zyxel_Melen

Hi @sjanssen15,

1. So all your tests are using the same cable, correct?
2. Since you mentioned that fixing the 2.5G link speed can make the link up for 5 minutes, could you use another cable to test?
3. Could you use the same cable to connect ports 9-11 as a loop to check the link status?
4. I checked my XGS1250-12 with 2.5G NIC, and ports 9-11 are both able to link to 2.5G. Could you share the S/N of your XGS1250-12?

Thanks~

sjanssen15

https://community.zyxel.com/en/discussion/comment/75579#Comment_75579

Hi Melen, it took a while but I replaced the complete cable inside the wall. Somehow it had issues with this CAT 6A cable. I think the shielding (grounding metal inside the cable) was damaged in the wall because I saw some of the grounding of the cable (outside was a little bit damaged). Can this impact auto-negationation even when all 8 are OK on the cable tester?

Replaced with CAT 6 cable and more protection and 2.5Gbe is now working automatically.