Domain Names/Static IP
Managing, controlling, and support for Custom Domain Names
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Ipv6 on outgoing mail?

I'm getting mail delivery failures to a company that is using ipv6. I'm completely ipv4 internally and on the firewall. But the bounce back messages (soft fail) refer to an ipv6 address. Do I need a ptr for the Comcast ipv6, or can I get it turned off?
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Re: Ipv6 on outgoing mail?

Does you mail server itself have an IPv6 address? Can you describe your server/network topology?

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Re: Ipv6 on outgoing mail?

Ipv6 is disabled on the Lan and router is not dual stack. Connectors on the the mail server are v4 only.
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Re: Ipv6 on outgoing mail?

All Comcast Gateways (CGs) run in dual stack mode IPV4 and IPV6. All CGs IPV6 can be disabled to stop all IPV6 processing if the network is only using IPV4 no problem.

 

 

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Re: Ipv6 on outgoing mail?

I've disabled it I thought on the modem. Is there additional step Comcast needs to do?
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Re: Ipv6 on outgoing mail?

No, if any customer can log into the CG then they can disable the IPV6 no problem.

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