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Cable Modem Interface going up and down

Hello,

I have an issue with an UTM 110/120 ans Software 8.309

We have attached a cable modem on ETH1 with DHCP.

The interface is going down and up 5-10 times a day.
It is down for about 1 Minute if I believe the Emails, but in real the interface seems to be up all the time.

I already tried to fix the interface on the UTM to 100 FDX Speed, this also didn't help.

Does someone have the same issue?

The strange thing is, it worked perfect over weeks, and the last 5 days this issue started, with no change on the UTM. The UTM has an uptime of 76 days.

Thank you for your help!

Best regards,
Dino

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0 Ol Deda over 12 years ago

What is your configuration and can you use the modem in bridge mode?
checking the MTU size will be helpful
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0 ALTEMO over 12 years ago

MTU 1500 and I use it in Bridge Mode.
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0 guawhitehawk over 12 years ago in reply to ALTEMO

I also experience that issue from time to time with KabelDeutschland and a Hitron Cable Modem in Bridge Mode. And the UTM uses normal Ethernet DHCP to connect to the internet. I haven`t changed anything else.
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0 Ol Deda over 12 years ago

Hi folks what you mean with DHCP?
DHCP from PPOE or Modem? If you are using PPOE, try lower MTU size (1492)
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0 ALTEMO over 12 years ago

No, we speak from DHCP to the Cable Modem.

The Cable Modem in Bridge mode passes the public IP to the UTM by DHCP.

We also have Hitron Modems.

Today this happend for the first time also with PPPOE Interfaces after upgrade to 9.1

The PPPOE Interface has MTU 1492 and is connected directly to a Dlink DSL Modem 321B.

Maybe this is a v8/v9 issue?
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0 guawhitehawk over 12 years ago in reply to ALTEMO

And the strange thing is, at home i have a Cisco EPC3212 EuroDocsis 3.0 Modem and not those problems.

it also seem that this only occurs if theres a bit more traffic on the line but it can be wrong since its at daylight when most people are on the internet
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0 Ol Deda over 12 years ago

have you checked the PPOE log or a hardware error?
Any printscreen of WAN configuration or the logs will be helpful
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0 BAlfson over 12 years ago

Quawhitehawk and ALTEMO, if BruceKConvergent were here, I think he'd suggest trying an even-lower MTU and then trying different combinations of fixed speeds and duplex on the 'Hardware' tab. He also would suggest that, for each combination, you should reboot both the UTM and the modem to force them to renegotiate the connection.

Cheers - Bob
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0 ALTEMO over 12 years ago

Tried different Speed and Duplex, also different MTU between 1450-1500 and restarted after every change. Problem still exists. Nothing in PPPOE Log and the Firewall is online all the time, so it seems that Emails with UP and DOWN are sent but the connection stays online all the time.
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0 ALTEMO over 12 years ago

By the way, I tried that on two different UTM 120 Rev. 4.

One with v9.1 and one with 8.309
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