Port 53 is open for DNS. Why would I need this? You need to have UDP 53 allowed for responses to DNS queries that your server sends, as UDP is a stateless protocol. Don't block it if you …

2014年6月4日 · Port 53 udp is reserved for DNS traffic. Even though you may have gotten OpenVPN to work on this port you are seriously blocking the server's ability to resolve DNS …

2013年11月8日 · I have what I believe to be an easy question. I want to lock down port 53 for outbound access to 3 of our internal DNS servers so that they're the only hosts that can …

2020年5月30日 · Recently both of our DNS servers stopped responding to incoming UDP on port 53, tested with dig and it works with TCP. They both have common ISP. Is there any way to …

2012年7月22日 · We have a Cisco ASA 5505 (v7.2 (3)) with a "fairly" normal configuration yet we have a problem where it appears UDP/53 traffic is denied on our inside network. here is output …

2018年2月9日 · Solved: This is the ACL applied inbound on the WAN interface. End user is having problems querying public DNS on UDP/53. 10 deny ip 10.0.0.0 0.255.255.255 any 20 …

2012年10月5日 · Hi I've setup Cisco router's DNS server... via "ip dns server" which in need for inside use.. however now if I do portscan from outside it shows port 53 opened. How do I block …

2024年12月17日 · The dns server sits at 157.141.245.10. Initially, i allowed in bound "permit udp <subnet and wc> host 157.141.245.10", but the traffic is still being blocked out to server. So i …

2016年2月11日 · All inbound UDP traffic for port 53 is blocked, except to the university's own DNS servers? That sounds suspiciously like an attempt at using DNS for censorship to me.

2012年6月25日 · Udp for small stuff like asking one address or something like that, and for larger transfers such as zone and so on it will switch to using Tcp. so yes it might work to test with …