Zephyr TCP Delay

[ofirshe]

Hi all,
I'm running a TCP server on Zephyr, and I'm experiencing a significant delay when a new client, one that the board hasn’t seen before, tries to connect. Even simple ping requests from the new client take a long time to get a response.
I assume this delay is due to the client's address not being updated in the ARP table quickly enough. Has anyone encountered this issue before, and if so, how did you resolve it?

My Ethernet Configuration:

CONFIG_NETWORKING=y
CONFIG_NET_UDP=y
CONFIG_NET_TCP=y
CONFIG_NET_IPV4=y
CONFIG_INIT_STACKS=y
CONFIG_NET_LOG=y
CONFIG_NET_CONFIG_SETTINGS=y
CONFIG_NET_CONFIG_NEED_IPV4=y
CONFIG_NET_CONFIG_MY_IPV4_ADDR="172.18.133.10"
CONFIG_NET_CONFIG_MY_IPV4_NETMASK="255.255.240.0"
CONFIG_NET_CONFIG_MY_IPV4_GW="172.18.143.254"
CONFIG_NET_L2_ETHERNET=y
CONFIG_NET_CONFIG_INIT_TIMEOUT=0
CONFIG_NET_CONTEXT_RCVTIMEO=y
CONFIG_NET_SOCKETS=y
CONFIG_POSIX_API=y
CONFIG_NET_TX_STACK_SIZE=8192
CONFIG_NET_RX_STACK_SIZE=8192
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=8192
CONFIG_NET_PKT_RX_COUNT=40
CONFIG_NET_PKT_TX_COUNT=40
CONFIG_NET_BUF_RX_COUNT=160
CONFIG_NET_BUF_TX_COUNT=160
CONFIG_NET_BUF_DATA_SIZE=256
CONFIG_NET_MAX_CONTEXTS=64

[jukkar]

What zephyr version are you using?
How long delays are we talking about?
If ARP needs to be done, then in worst case it can take some time to finish, not sure how you could speed this up.

[ofirshe]

@rlubos So do you think it's a board specific issue ? What could be missing ?

[ofirshe]

Hi @decsny,

Could you or someone else at NXP check this issue? When gratuitous ARP transmission is enabled, the RT1060 should send a packet as soon as the interface is up after boot. However, that’s not what I’m seeing on my side.

[rlubos]

@rlubos So do you think it's a board specific issue ? What could be missing ?

Definitely nothing generic because gratuitous ARP worked just as expected on 3 different platforms I've tested, just as I wrote above.

[ofirshe]

Hey @rlubos,

Could you kindly share the configuration you used here? I want to make sure I'm running with the same settings and determine if this issue is board-specific or something on my end before opening an issue on Zephyr.

Thank you.

[rlubos]

I ran zperf sample with gratuitous ARP configs added:

CONFIG_NET_MGMT_EVENT=y  
CONFIG_NET_MGMT_EVENT_INFO=y  
CONFIG_NET_ARP_GRATUITOUS=y  
CONFIG_NET_ARP_GRATUITOUS_TRANSMISSION=y 

[ofirshe]

Opened related issue #85957