Hi, I am running on a FX30S LTE-M WP77 with legato 19.11.5… I can successufly create a data connection, resolve hostname using getaddrinfo. I then close the socket. I use le_data_Request and socket / close… However any subsequent attempts to resolve a hostname then fail with "Temporary failure in name resolution " cm data, shows there is a connection with DNS and gateway IP addresses. root@fx30s:~# cm data Index: 1 APN: ***** PDP Type: IPV4 Connected: yes Interface: rmnet_data0 Family[IPv4]: inet IP[IPv4]: ******** Gateway[IPv4]: ********* Dns1[IPv4]: 8.8.8.8 Dns2[IPv4]: 212.9.0.136 ping my.host.name nslookup my.host.name 8.8.8.8 ping 8.8.8.8 all fails. They where fine before the initial connection in the legato app. resolv.conf is correctly populated. Any thoughts? Thanks,Karl

If you disconnect data connection by “cm data connnect -1”, and thr restart data channel by “cm data”, can it be resolved?

Just tries that… it did not work.

No I don’t think so… after reboot it work every time… the problem is repeatable… Device reboots connected to bearer created data connection getaddrinfo and open socket send /rec data close socket ping, nslookup etc don’t work anymore Thanks,

then how about you do radio on off? cm radio off cm radio on you might also need to capture wireshark log on rmnet interface to see what happens inside

busy setting up tcpdump so I can do just that… will try radio on off… but that would not be a solution…

you can see here for wireshark log capturing: [image] View pings sent from an external device to mangoh red Legato Application Framework @jyijyi Is there a step by step process you can provide?

I just get no reply… when “ping 8.8.8.8” [image]

even after re-estabishment of data channel? even after restart of radio by “cm radio”? How do you reproduce the issue? cm data connect ping 8.8.8.8 wait for some time ping does not work

it seems turning radio off then on resolves the issue. To recreate… I start my app which a) turns the radio on (if off) with le_mrc_SetRadioPower(LE_ON) b) wait for network registration (in the le_mrc_AddNetRegStateEventHandler) c) request data connection with le_data_Request() d) wait for connection in le_data_AddConnectionStateHandler At this point I can ping successfully to 8.8.8.8 then in my app it e) get IP address for hostname using getaddrinfo and getnameinfo f) create a non blocking socket using “connect” g) send/receive data over socket h) close the socket once done. At this point I cannot ping to 8.8.8.8 anymore… I get no response as per tcpdump… cm radio and cm data suggest I still have a connection… however I can’t successfully send/rec anything over rmnet… cm data connect -1 followed by cm data connect does not seem to solve it… I need to cm radio off and then cm radio on… However that is a problem as I cannot turn the radio off and on for each socket connection… I assume I am doing something wrong… but can’t work out what…

Getaddrinfo failing after closing socket

Uncategorized

jyijyi February 27, 2023, 4:07pm 8

you can see here for wireshark log capturing:

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Getaddrinfo failing after closing socket

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