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Popup Hotspot Using ISR 1000 with WiFi/LTE for Teleworkers and Micro Branchesr
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Beginner

IPv6 DNS lookup instead of IPv4

Hey All,

I have 9500 series Switches which is facing the firewall and plays the DNS Proxy role for clients and everything is perfect. What is the problem I want to renew license with CSSM and therefore it needs to contact tools.cisco.com. I have tested and the switch has ip connectivity to internet, ping works. But the problem is when I try to telnet tools.cisco.com 443 I see that it tries to contact IPv6 address. I tested several other domain names and all are the same with IPv6. I have disabled IPv6 unicast-routing globally, but it does not help.

 

telnet tools.cisco.com 443
Trying 2001:420:1201:5::A, 443 ...
% Destination unreachable; gateway or host down

 

Any help is appreciated.

 

 

Everyone's tags (4)
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Beginner

Re: IPv6 DNS lookup instead of IPv4

Hi,

 

Did you solve this?

I have this excact same issue on a C1100 router

 

 

BR

Mats

 

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Collaborator

Re: IPv6 DNS lookup instead of IPv4

Hi,

 

    First try configuring this: "call-home/http resolve-hostname ipv4-first", clear your DNS cache and see if it works now; if still not, try rebooting; if still not, hardcode the IPv4 address in the call-home URL (instead of the name), get the job done and raise a TAC case.

 

Regards,

Cristian Matei.

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