IP Addressing: NAT Configuration Guide, Cisco IOS XE Release 3S - SIP ALG Hardening for NAT and Firewall

Publisher

Cisco Systems

URL

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_nat/configuration/xe-3s/nat-xe-3s-book/iadnat-fw-sip-alg-hardng.html

Published

2014-07-10

Updated

unknown

Accessed

2026-09-25

HTTP status

200

License

Cisco copyright; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

• On Cisco IOS and IOS XE NAT, NAT support for SIP (the SIP ALG) is enabled by default on port 5060. in context
• Cisco documents the no ip nat service sip command for disabling NAT support for SIP on IOS XE. in context
• The Cisco IOS XE SIP ALG reads the Via, Contact and Record-Route headers to create firewall pinholes and NAT translation doors. in context
• Cisco states that the IOS XE SIP ALG does not provide any security features. in context

Cite this source record

APA

WarmTransfer. (2014, July 10). IP Addressing: NAT Configuration Guide, Cisco IOS XE Release 3S - SIP ALG Hardening for NAT and Firewall. WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-iosxe-3s-sip-alg-hardening

BibTeX

@misc{warmtransfer-cisco-iosxe-3s-sip-alg-hardening,
  title  = {IP Addressing: NAT Configuration Guide, Cisco IOS XE Release 3S - SIP ALG Hardening for NAT and Firewall},
  author = {{WarmTransfer}},
  year   = {2014},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-iosxe-3s-sip-alg-hardening},
  note   = {Cisco Systems, accessed 2026-09-25}
}