IPv4/IPv6 Not Working on RM520N-GL and T-Mobile

Technical Subjects
1

Hello,

I’m trying to setup an RM520N-GL with T-Mobile Business Internet. IPv6 was initially working. However, I upgraded the firmware to RM520NGLAAR01A07M4G_01.203.01.203, and now I cannot seem to get IPv6 work. IPv4 has never worked. Some command outputs are below.

Does anyone have any thoughts? Could it be TTL related?

Thanks,
Matt

AT+QGMR
RM520NGLAAR01A07M4G_01.203.01.203

OK
at+qcfg=?
+QCFG: “rrc”,(0-5)
+QCFG: “hsdpacat”,(6,8,10-24)
+QCFG: “hsupacat”,(5,6)
+QCFG: “pdp/duplicatechk”,(0,1)
+QCFG: “risignaltype”,(“respective”,“physical”)
+QCFG: “lte/bandprior”,(1-43),(1-43),(1-43)
+QCFG: “volte_disable”,(0,1)
+QCFG: “diversity/config”,(4,6),(1-4),(0)
+QCFG: “div_test_mode”,(0,1)
+QCFG: “usbspeed”,(“20”,“311”,“312”)
+QCFG: “data_interface”,(0,1),(0,1)
+QCFG: “pcie/mode”,(0,1)
+QCFG: “wifi/model”,(“wcn6856”,“fc64e”,“fc06e”,“fc06e-33”,“fc60e”,“fc08e”)
+QCFG: “pcie_mbim”,(0,1)
+QCFG: “sms_control”,(0,1),(0,1)
+QCFG: “call_control”,(0,1),(0,1)
+QCFG: “usb/maxpower”,(0-900)
+QCFG: “efratctl”,(0,1)
+QCFG: “gatewayset”,(0,1)[,]
+QCFG: “netmaskset”,(0,1)[,]
+QCFG: “clat”,(0,1),(0,1),,(0,32,40,48,56,64,96),,(0,1),(0,1,2,4,8 ),(0,1),(0,1),(0,1,2),(0,1,2)
+QCFG: “usage/apmem”
+QCFG: “enable_gea1”[,(0,1)]
+QCFG: “uart”,(0,1),(0,1)
+QCFG: “rollback”,(0,1)

OK
AT+QCFG=“CLAT”
+QCFG: “clat”,1,1,“”,0,“ipv4only.arpa.”,0,0,1,1,2,2

OK
AT+QMAP=“MPDN_rule”
+QMAP: “MPDN_rule”,0,0,0,0,0
+QMAP: “MPDN_rule”,1,0,0,0,0
+QMAP: “MPDN_rule”,2,0,0,0,0
+QMAP: “MPDN_rule”,3,0,0,0,0

OK
AT+QETH=“ipptmac”
+QETH: “ipptmac”,FF:FF:FF:FF:FF:FF

OK
at+qmap=?
+QMAP: “WWAN”,(0,1),(1-42),<IP_family>,<IP_address>
+QMAP: “DMZ”,(0,1),(4,6),<IP_address>
+QMAP: “GRE”,(0,1),<IP_address>
+QMAP: “LAN”,<IP_address>
+QMAP: “LANIP”,<LAN_IP_start_address>,<LAN_IP_end_address>,<GW_IP_address>,
+QMAP: “VLAN”,(2-255),(“enable”,“disable”),(1-3,11-13)
+QMAP: “MPDN_rule”,(0-3),(1-16),(0,2-255),(0-3),(0,1),<IPPT_info>
+QMAP: “IPPT_NAT”,(0,1)
+QMAP: “connect”,(0-3),(0,1)
+QMAP: “auto_connect”,(0-3),(0,1),(1-16)
+QMAP: “MPDN_status”
+QMAP: “AP_rule”,(0-3),(0-3)
+QMAP: “SFE”,(“enable”,“disable”)
+QMAP: “domain”,<domain_name>
+QMAP: “DHCPV4DNS”,(“enable”,“disable”)
+QMAP: “DHCPV6DNS”,(“enable”,“disable”)
+QMAP: “NAT_timeout”,(1-4,6),
+QMAP: “port_mapping”,(“add”,“get”,“del”),<0-3>,<private_IP>,<private_port>,,

OK
at+qmap=“wwan”
+QMAP: “WWAN”,0,1,“IPV4”,“0.0.0.0”
+QMAP: “WWAN”,0,1,“IPV6”,“0:0:0:0:0:0:0:0”

OK
AT+CGDCONT?
+CGDCONT: 1,“IPV4V6”,“fast.t-mobile.com”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0 ,0,“”,0
+CGDCONT: 2,“IPV4V6”,“ims”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”, ,1
+CGDCONT: 3,“IPV4V6”,“sos”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,1,“”, ,1
+CGDCONT: 4,“IPV4V6”,“tmus”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“” ,0
+CGDCONT: 5,“IPV4V6”,“h2g2”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“” ,0
+CGDCONT: 6,“IPV4V6”,“pcweb.tmobile.com”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0 ,0,“”,0

OK

2

Assuming APN is correct, reconfigure this context as IPV6 only, then restart/reset the modem.
Run once AT+CGPIAF=1,1,1,0 for better output formatting and then check with
AT+CGPADDR and AT+CGCONTRDP=1

3

Thank you very much. I really appreciate your help. I reconfigured to IPv6, and confirmed the APN is correct. The the outputs from the commands you listed are below. Also, my host computer seems to be getting an IPv6 address. However, I cannot ping any IPv6 addresses (e.g., Google’s servers).

Mobile Broadband adapter Cellular 2:

Connection-specific DNS Suffix . :
IPv6 Address. . . . . . . . . . . : 2607:fb90:b59a:2c1:60f7:60da:dc1b:699c
IPv6 Address. . . . . . . . . . . : 2607:fb90:b59a:2c1:6158:6c65:c56e:e472
Temporary IPv6 Address. . . . . . : 2607:fb90:b59a:2c1:fd4a:1f37:55d:f9af
IPv4 Address. . . . . . . . . . . : 192.0.0.2
Subnet Mask . . . . . . . . . . . : 255.255.255.224
Default Gateway . . . . . . . . . : 2607:fb90:b59a:2c1:c4e5:fedf:816d:8038
fe80::c4e5:fedf:816d:8038%29
192.0.0.1

AT+CGPIAF=1,1,1,0
OK
AT+CGPADDR
+CGPADDR: 1,“2607:FB90:B59A:02C1:0AD3:1B57:4FD4:21F4”
+CGPADDR: 2,“0.0.0.0”,“0000:0000:0000:0000:0000:0000:0000:0000”
+CGPADDR: 3,“0.0.0.0”,“0000:0000:0000:0000:0000:0000:0000:0000”
+CGPADDR: 4,“0.0.0.0”,“0000:0000:0000:0000:0000:0000:0000:0000”
+CGPADDR: 5,“0.0.0.0”,“0000:0000:0000:0000:0000:0000:0000:0000”
+CGPADDR: 6,“0.0.0.0”,“0000:0000:0000:0000:0000:0000:0000:0000”

OK
AT+CGCONTRDP=1
+CGCONTRDP: 1,0,“fast.t-mobile.com”,“2607:FB90:B59A:02C1:0AD3:1B57:4FD4:21F4”, “FE80:0000:0000:0000:B46D:57FF:FE45:4545”, “FD00:976A:0000:0000:0000:0000:0000:0009”, “FD00:976A:0000:0000:0000:0000:0000:0010”

OK
at+qmap=“wwan”
+QMAP: “WWAN”,0,1,“IPV4”,“0.0.0.0”
+QMAP: “WWAN”,0,1,“IPV6”,“0:0:0:0:0:0:0:0”

OK

4

Please take a look: RM520N-GL IP Passthrough with Network Adatper Mode

How the modem is connected? Is it a direct Ethernet connection between the PC and some Ethernet-to-M.2 adapter?

5

The modem is connected via eth and IP passthrough. Also, I took a look at that article before. I couldn’t figure anything out from it. The mpdn_rules didn’t seem to make any difference. Ping via IPv6 doesn’t work.

6

What is your current MPDN_rule?

7

I tried both of the following without any luck.
* at+qmap=“mpdn_rule”,0,1,0,0,1
* at+qmap=“mpdn_rule”,0,1,0,1,1,“FF:FF:FF:FF:FF:FF”

I think the problem is might have something to do with my PDP context. When I run AT+CPOL?, I receive +CME ERROR: 3. CME ERROR 3 means “Operation not allowed”. For reference, my PDP contexts are below. Also, the APN is correct. Do you have any idea how to get more meaningful logs?

AT+CGDCONT?
+CGDCONT: 1,“IPV4V6”,“fast.t-mobile.com”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”,0
+CGDCONT: 2,“IPV4V6”,“ims”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”,1
+CGDCONT: 3,“IPV4V6”,“sos”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,1,“”,1
+CGDCONT: 4,“IPV4V6”,“tmus”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”,0
+CGDCONT: 5,“IPV4V6”,“h2g2”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”,0
+CGDCONT: 6,“IPV4V6”,“pcweb.tmobile.com”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0,“”,0

8

at+qmap="mpdn_rule",0,1,0,1,1,"FF:FF:FF:FF:FF:FF" looks good to me.
As mentioned earlier, I would make the context IPv6 only, i.e. AT+CGDCONT=1,"IPV6","fast.t-mobile.com"
I would also check AT+QMAP="auto_connect"

However, if pcweb.tmobile.com in context 6 is there by purpose, then you can try referring to this context instead of context 1 in your mpdn_rule.

9

Thank you for all your help. I’m not sure what happened, but something got corrupt or switched on the modem. Running AT+QCFG=“ResetFactory” and reconfiguring fixed everything.

10

Just a suggestion mate, in case you faced any irregular issues in module, the best way is to re-flash it. Then start over the configuration. I know it’s painful, but it’s always working solution. Specially when issue is on profiles, as according to firmware update notes, there are hidden parameters which if you change profiles 1-3, then those parameters are discarded
Always define your APN after the first 3 settings.
Cheers