Microsoft says to allow Direct Routing signaling to and from all the listed Microsoft Teams IP ranges, not only the addresses returned by DNS.

Checked 2026-09-25

Configure your firewall to allow signaling traffic to and from all Microsoft Teams IP ranges, not only the addresses returned from DNS queries.
Vendor
Microsoft
Product
Teams Phone Direct Routing
Subsystem
SIP signaling - firewall
Deployment
multi-tenant
Region
not restricted
Release range
current as of 2026-09-25
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP scanning and telephony denial of service: source note sip-scanning-tdos-ms-dr-firewall-all-ranges. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-scanning-tdos-ms-dr-firewall-all-ranges

BibTeX

@misc{warmtransfer-claim-sip-scanning-tdos-ms-dr-firewall-all-ranges,
  title  = {SIP scanning and telephony denial of service: source note sip-scanning-tdos-ms-dr-firewall-all-ranges},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-scanning-tdos-ms-dr-firewall-all-ranges},
  note   = {Source note sip-scanning-tdos-ms-dr-firewall-all-ranges, checked 2026-09-25}
}

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