netif_set_mtu_ext(9)

💖 netif_set_mtu_ext(9) 💖

okay so hi bestie, welcome to the Kernel API Manual ✨ — yes that's the manual this page lives in, and yes you're about to read a whole manpage about changing one number. slay. let's go 🎀

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🌸 NAME 🌸

netif_set_mtu_ext — Change maximum transfer unit 🦋

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⭐ SYNOPSIS ⭐

int netif_set_mtu_ext (struct net_device *dev , int new_mtu , struct
       netlink_ext_ack *extack );

like, that's the whole signature. three args. no cap. 💅

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🫶 ARGUMENTS 🫶

• dev — the device 👑 like, the network device you're doing this to.
• new_mtu — the new transfer unit ✨ the fresh number you want it to be.
• extack — netlink extended ack 💌 the extended-ack struct that rides along.

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💜 DESCRIPTION 💜

Change the maximum transfer size of the network device. that's it. that's the vibe. one job, done iconically 🧚

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🌈 RETURN 🌈

0 on success, -errno on failure. so like, zero means you ate, and a negative errno means 😭 something went sideways.

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🔥 SEE ALSO 🔥

the whole squad, fr fr — these all live in the kernel file ./net/core/dev.c:

• dev_add_pack(9)
• __dev_remove_pack(9)
• dev_remove_pack(9)
• dev_get_iflink(9)
• dev_fill_metadata_dst(9)
• netdev_napi_by_id_lock(9)
• __dev_get_by_name(9)
• dev_get_by_name_rcu(9)
• netdev_get_by_name(9)
• __dev_get_by_index(9)
• dev_get_by_index_rcu(9)
• netdev_get_by_index(9)
• dev_get_by_napi_id(9)
• netdev_get_by_index_lock(9)
• netdev_get_name(9)
• dev_getbyhwaddr_rcu(9)
• dev_getbyhwaddr(9)
• netdev_get_by_flags_rcu(9)
• dev_valid_name(9)
• __dev_alloc_name(9)
• dev_alloc_name(9)
• dev_get_alias(9)
• netdev_features_change(9)
• __netdev_notify_peers(9)
• netdev_notify_peers(9)
• dev_disable_gro_hw(9)
• register_netdevice_notifier(9)
• unregister_netdevice_notifier(9)
• register_netdevice_notifier_net(9)
• unregister_netdevice_notifier_net(9)
• call_netdevice_notifiers_info(9)
• call_netdevice_notifiers_info_robust(9)
• call_netdevice_notifiers(9)
• call_netdevice_notifiers_mtu(9)
• dev_forward_skb(9)
• dev_nit_active_rcu(9)
• netif_setup_tc(9)
• netif_set_real_num_rx_queues(9)
• netif_set_real_num_queues(9)
• netif_set_tso_max_size(9)
• netif_set_tso_max_segs(9)
• netif_inherit_tso_max(9)
• netif_get_num_default_rss_queues(9)
• netif_device_detach(9)
• netif_device_attach(9)
• dev_loopback_xmit(9)
• __dev_queue_xmit(9)
• rps_flow_is_active(9)
• rps_may_expire_flow(9)
• __netif_rx(9)
• netif_rx(9)
• netdev_is_rx_handler_busy(9)
• netdev_rx_handler_register(9)
• netdev_rx_handler_unregister(9)
• netif_receive_skb_core(9)
• netif_receive_skb(9)
• netif_receive_skb_list(9)
• __napi_schedule(9)
• napi_schedule_prep(9)
• __napi_schedule_irqoff(9)
• netif_threaded_enable(9)
• netif_queue_set_napi(9)
• napi_disable(9)
• napi_enable(9)
• netdev_has_upper_dev(9)
• netdev_has_upper_dev_all_rcu(9)
• netdev_has_any_upper_dev(9)
• netdev_master_upper_dev_get(9)
• netdev_has_any_lower_dev(9)
• netdev_upper_get_next_dev_rcu(9)
• netdev_lower_get_next_private(9)
• netdev_lower_get_next_private_rcu(9)
• netdev_lower_get_next(9)
• netdev_lower_get_first_private_rcu(9)
• netdev_master_upper_dev_get_rcu(9)
• netdev_upper_dev_link(9)
• netdev_master_upper_dev_link(9)
• netdev_upper_dev_unlink(9)
• netdev_bonding_info_change(9)
• netdev_get_xmit_slave(9)
• netdev_sk_get_lowest_dev(9)
• netdev_lower_state_changed(9)
• netif_get_flags(9)
• netif_pre_changeaddr_notify(9)
• dev_get_phys_port_id(9)
• dev_get_phys_port_name(9)
• netif_get_port_parent_id(9)
• netdev_port_same_parent_id(9)
• netdev_change_proto_down_reason_locked(9)
• dev_change_xdp_fd(9)
• dev_index_reserve(9)
• netdev_update_features(9)
• netdev_change_features(9)
• netif_stacked_transfer_operstate(9)
• register_netdevice(9)
• register_netdev(9)
• netdev_wait_allrefs_any(9)
• dev_get_stats(9)
• dev_fetch_sw_netstats(9)
• dev_get_tstats64(9)
• netdev_sw_irq_coalesce_default_on(9)
• alloc_netdev_mqs(9)
• free_netdev(9)
• alloc_netdev_dummy(9)
• synchronize_net(9)
• unregister_netdevice_queue(9)
• unregister_netdevice_many(9)
• unregister_netdev(9)
• netdev_increment_features(9)
• netdev_compute_master_upper_features(9)
• netdev_drivername(9)

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ok that's literally the whole page, go forth and set some MTUs bestie 🦋✨

kisses, this page shipped from ./net/core in October 2026 — Kernel API Manual era, periodt 💅🎀