Inquiries about PBF nexthop settings when the ISP is a DHCP Client

[HilineISP_Tech]

1. Issue: PBF does not operate normally when the public IP received from the line is a dynamic IP

2. Measures
- If the circuit IP is a static IP, check the normal operation by inserting the gateway into the PBF – Nexthop setting
- If the line IP is a dynamic IP, check the normal operation by inserting the gateway into the PBF – Nexthop setting
 At this time, the upper line modem does not distribute only one band by DHCP, but the IP may change to another band.
Due to the problem that the assigned IP band may be deleted from the modem due to carrier circumstances and assigned to another band
If the line IP is a dynamic IP, it is not possible to directly enter the gateway in the PBF – Nexthop setting.

3. Final question: How to use PBF when the line IP is dynamic?

please answer about my question

[BPry]

@HilineISP_Tech,

What I would do in this situation is change the next hop to utilize FQDN and setup the untrust interface with DDNS so that the FQDN in question is updated automatically in the event that the address changes. That's the only way that you'll be able to use just the firewall itself to fix this issue.

[OtakarKlier]

Hello,

I would do the same as BPry would. Use FQDN. If not get the ISP to provide a static gateway since that would be the next hop. Could you maybe provide a basic diagram of the setup? This way we might be able to see the big picture better.

Regards,