ASUS Rapture DHCP Not working properly (Bridge Mode)

@XfinityChe 

I was referred to you for assistance

See if anything from these two pinned troubleshooting topics at the top of this help board applies;

https://forums.xfinity.com/conversations/your-home-network/asus-ax86u-isp-dhcp-not-working/62a39a42382dc22d0f772fbf 

https://forums.xfinity.com/conversations/your-home-network/isps-dhcp-not-functioning-fix-for-asus-router-owners-probably-others/621bc857aa6a0b79e9624505 

i followed both of those prior to this post. does not work

Looks like that one doesn't have a manual, just a quick start guide so there isn't much to suggest on options.  It does however look like you can use a 10G Asus port for WAN, or configure one of the 2.5G/1G Asus ports for WAN.  Use the orange/red stripe port on the Xfinity gateway.

Maybe see if one of those works better?  Pull power on both the Asus and Xfinity gateway after you change the Asus config.  If that doesn't help, what does it show you for DHCP options on the configuration page?

I'm running through the 2.5 g port on both modem and router already. But have tried various other ports. The router is pretty extensive I have class identifiers that can be set for option 60 and 61 for DHCP. I have tried DHCP query frequency in normal and aggressive. Mac cloning and so fourth.

I haven't messed with the ip pools for starting and ending, could this be an issue?

yes i can use IPV6m i just set to native and disabled the DHCP-PD, wants me to set the Lan IPV6 address and prefix length?

https://dlcdnets.asus.com/pub/ASUS/wireless/GT-AXE11000/E18581_GT-AXE11000_UM_WEB.pdf

i was able to find the actual manual for my exact model, may help you since your kind of in the blind @flatlander3 

Yeah.  Native.  Probably right.  You don't want to run the dhcp-pd and static IPV6 inside, so that is probably right too.  That was more of a ppoe thing....perhaps with some ISPs....

On the internal LAN interface, is there an option to select IPV6 configuration type?  That should be "track interface", not "IPV6". 

stateless or stateful are the only options

@flatlander3 i should mention as well everything works seemless without the modem in bridge mode. For whatever reason on the asus side it just will not get the Wan ip and such from xfinity when bridge mode is on 

"stateless or stateful are the only options"

Yeah, I ran into an odd thing with that too with a firewall.  That's the DHCP6 Router advertisements.

Unmanaged = it's done with SLAAC -- dhcp6 disabled

Managed = The firewall will send out RA packets and addresses will only be assigned to clients using DHCPv6.

Assisted = The firewall will send out RA packets and addresses can be assigned to clients by DHCPv6 or SLAAC.

Stateless DHCP = The firewall will send out RA packets and addresses can be assigned to clients by SLAAC while providing additional information such as DNS and NTP from DHCPv6.

What ended up working with Xfinity?  Assisted, but Managed didn't work at all.  Why?  Now that's a mystery.  Stateless doesn't work.  I don't think they're using SLAAC.  So if you got just the two options, try Stateful, even though that might not exactly be technically right.  Xfinity has zero guidance here.