A network adapter includes a port and one or more circuits. The port is to send packets to a network in accordance with a Remote Direct Memory Access over Converged Ethernet (RoCE) protocol. The one or more circuits are to decide whether a packet is permitted to undergo Adaptive Routing (AR) in being routed through the network, to mark the packet with an indication of whether the packet is permitted to undergo AR, and to send the marked packet to the network via the port.