MTU monitoring and MSS clamping

March 2026

Path-MTU problems are some of the most confusing failures to troubleshoot. Swift Fox now measures MTU across your network and works around problems automatically with MSS clamping. Behind the scenes, March was heads-down on the new balancing engine that shipped in April.

MTU monitoring and TCP MSS clamping New

Swift Fox now probes and monitors path MTU across your network and can clamp TCP MSS automatically — catching the classic "some websites don't load" fragmentation problems before a customer calls about them.

Routing analysis: tunnels view Improved

The routing analysis screen gained a tunnels tab and MTU details, so you can see every TE tunnel, its path, and its constraints in one place.

The tunnels tab of the routing analysis screen: eight established TE tunnels with their gateways, rates, hop counts, MPLS labels, and the per-backhaul path each one takes through the network

Balancing engine rework underway Improved

The auto traffic balancing engine was rebuilt around a faster LP solver with two-pass spreading over redundant backhauls, and native RouterOS v6 MPLS/TE support in the new engine. It went live the following month.

PFO fix for very large networks Fixed

PFO now splits router commands that exceed RouterOS's 4096-character limit — shaping syncs reliably no matter how many packages you have.