Set interface MTU

Set jumbo MTU and bring link up; note: path MTU must match end-to-end

ip link set dev <name> mtu 9000 && ip link set dev <name> up
tool
iproute212 commands
tags
iproute2networkperformance

More iproute2 commands

  • JSON addr to jq
    ip -j a | jq -r '.[] | select(.operstate=="UP") | .ifname + " " + (.addr_info[]?.local // "-")'

    Machine-readable interface dump; list UP links with their local IPs

  • Which route is chosen
    ip route get <ip>

    Show the exact route, src IP and oif the kernel picks for a destination

  • Source-based policy routing
    ip rule add from <ip> table 100 && ip route add default via 192.168.1.1 dev <name> table 100

    Route by source IP via a separate table; check with ip rule show

  • Run command in netns
    ip netns add test && ip netns exec test ip -br a

    Create an isolated network namespace and run commands inside it

  • Inject latency and loss
    tc qdisc add dev <name> root netem delay 100ms loss 1% && tc -s qdisc show dev <name>

    Simulate WAN latency/packet loss for testing; remove with tc qdisc del

all 12 iproute2 commands