2021年12月28日 · In other words, RTR-Site1 encapsulates ESP packets inside UDP/4500 for Source and Destination Ports. After this encapsulation, now NAT device can translate the ESP packets. It will change the source port from 4500 to a random port and the source IP address from 172.16.1.1 to 100.1.1.1, and kept the destination port 4500

Hi Kranthi, Adding to what the other guys posted, using udp ports 500/4500 would come in place when nat is used, esp protocol does not use any port, so to be able to pass the esp packet through the nat devices, the source private address should be translated to a public address with the addition of the translated source port, since that packet does not has any source port, nat devices would ...

2011年5月23日 · This UDP port 4500 is used to PAT ESP packet over ipsec unaware NAT device. if this UDP encapsulation in not done then the ESP packet will be dropped and data will not flow. well my question is : the ESP packet starts after 9 th packet of quick mode. but the NAT-T is detected and changes the port from udp 500 to 4500 on 5th packet. why is this ...

2010年10月27日 · So, ESP does not use UDP port, it is an IP protocol in the same sense that UDP and TCP are IP protocols. if the PAT device allows only TCP and UDP traffic, ESP packets are dropped. IKE uses UDP port 500, but not ESP. NAT-T encapsulates ESP packets to UDP with Source and Destination ports 4500. So, ESP packets can be translated from PAT router.

2023年2月1日 · In other words, RTR-Site1 encapsulates ESP packets inside UDP/4500 for Source and Destination Ports. After this encapsulation, NAT device can now translate the ESP packets. It will change the source port from 4500 to a random port and the source IP address from 172.16.1.1 to 100.1.1.1 and kept the destination port 4500

2020年2月21日 · Hi, we've got classic DMVPN scheme with central router and spokes, all IOS routers. One of remote sites has bad ISP, which filters GRE and ESP (i beleive they filter all except tcp, udp and icmp). Is there any way to force spoke using udp/4500 instead ESP? Any over suggestions? Spoke's IP is dynamic...

But when the tunnel is going through NAT use sues different ports. It uses port 4500 for both the Control and Data Plane. So I'm a bit confused as how this works. UDP port work at Layer 4, so so far moving the data from 4500 to 500 is clear, but why is port 4500 allowed and 4500 disallowed. That seem weird to me.

2021年9月1日 · Also enabling Nat-Traversal on the gateways resolves the problem with the authenticity and integrity checks as well, as they are now aware of these changes.During phase 1, if NAT Traversal is used, one or both peer's identify to each other that they are using NAT Traversal, then the IKE negotiations switch to using UDP port 4500.

2011年4月17日 · Hi if y need to enable VPN IPSec through the firewall. y just need to need to allow the port 4500?

2022年7月19日 · Re: UDP 500 et 4500 Bonjour, les 2 réponses m’intéressent. En faite j’ai une application téléphonique (VoWiFi) qui demande si les 2 sont bien ouverts pour transférer les communications via le wifi quand le réseau mobile est trop faible.