[ZBX-20133] Timeout while connecting via SNMP, but device available Created: 2021 Oct 27  Updated: 2023 Jan 10  Resolved: 2023 Jan 10

Status: Closed
Project: ZABBIX BUGS AND ISSUES
Component/s: Proxy (P), Server (S)
Affects Version/s: 5.4.5
Fix Version/s: None

Type: Problem report Priority: Trivial
Reporter: Yurii Polenok Assignee: Igor Gorbach (Inactive)
Resolution: Won't fix Votes: 0
Labels: interface, snmp
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified
Environment:

CentOS Linux release 8.4.2105
zabbix-proxy-sqlite3-5.4.5-1.el8.x86_64
net-snmp-libs-5.8-20.el8.x86_64
net-snmp-utils-5.8-20.el8.x86_64

Attachments: PNG File image-2021-10-27-17-34-27-260.png     PNG File image-2021-10-28-13-14-22-792.png    

 Description   

Steps to reproduce:

  1. Add Opengear device with SNMPv3 interface and one item to check SNMP availability.
  2. Wait or "Execute item" from Zabbix frontend.

Result:

  1. 1277296:20211027:142127.795 In get_values_snmp() host:'a-cm03.a.com' addr:'10.216.216.167' num:1
1277296:20211027:142127.795 In zbx_snmp_open_session()
1277296:20211027:142127.816 SNMPv3 [[email protected]:161]
1277296:20211027:142127.816 End of zbx_snmp_open_session()
1277296:20211027:142127.816 In zbx_snmp_process_standard()
1277296:20211027:142127.816 In zbx_snmp_translate() OID:'1.3.6.1.2.1.1.3.0'
1277296:20211027:142127.816 End of zbx_snmp_translate() oid_translated:'1.3.6.1.2.1.1.3.0'
1277296:20211027:142127.816 In zbx_snmp_get_values() num:1 level:0
1277296:20211027:142227.875 zbx_snmp_get_values() snmp_synch_response() status:2 s_snmp_errno:-24 errstat:-1 mapping_num:1
1277296:20211027:142227.875 End of zbx_snmp_get_values():NETWORK_ERROR
1277296:20211027:142227.875 End of zbx_snmp_process_standard():NETWORK_ERROR
1277296:20211027:142227.875 In zbx_snmp_close_session()
1277296:20211027:142227.875 End of zbx_snmp_close_session()
1277296:20211027:142227.875 getting SNMP values failed: Timeout while connecting to "10.216.216.167:161".
1277296:20211027:142227.875 End of get_values_snmp()
1277296:20211027:142227.875 In zbx_deactivate_item_interface() interfaceid:52883 itemid:1397825 type:20
1277296:20211027:142227.875 zbx_deactivate_item_interface() errors_from:1635283043 available:2
1277296:20211027:142227.875 End of zbx_deactivate_item_interface()
  2. But the host is available when checking with snmpwark from the zabbix-proxy console
[root@zabbix-proxy-01 ~]# time snmpwalk -On -v 3 -r 0 -t 30 -a MD5 -l authPriv -u nnm-switches -A q1w2e3r4 -x DES -X w2e3r4t5 10.216.216.167 1.3.6.1.2.1.1.3.0
.1.3.6.1.2.1.1.3.0 = Timeticks: (60699381) 7 days, 0:36:33.81

real    0m0.032s
user    0m0.025s
sys     0m0.003s
  1. Also item successfully receives a response when checking with Test in the Zabbix frontend.

Expected:
SNMP item receives value and SNMP interface available.

 Comments   
Comment by Igor Gorbach (Inactive) [ 2021 Oct 28 ]

Hello!

ZBX - is a bug tracker for identifying and fix some issues in Zabbix functionality
Cannot reproduce your situation, looks like, that you have some missconfiguration for host SNMP interface settings
You can get some help in
Zabbix International Community in Telegram
or
Zabbix Forum

Comment by Yurii Polenok [ 2021 Oct 28 ]

There is one SNMP interface with simple configuration.
Everything works from a console tool, even from Zabbix with a Test button, but does not work in the item itself.
It also works for a while after reloading the snmp cache or restarting the proxy, after a few hours it fails again.
Please try again to find the reason. What additional information can I provide?
Timeout in the proxy and server configuration files is 30.

Comment by Igor Gorbach (Inactive) [ 2021 Oct 28 ]

Regarding on your description

Everything works from a console tool, even from Zabbix with a Test button, but does not work in the item itself.
It also works for a while after reloading the snmp cache or restarting the proxy, after a few hours it fails again.

It looks like  a potential problem with bulk request working on device side

But, let's check it more carefully, to find a possible bug

Please, provide a tcpdump filtered by UDP:161 for mentioned IP for period when problem occuring (Start working and failing)
Stop proxy
Start tcpdump
Start proxy
wait for the problem
Stop tcpdump
and attach it to the issue

Regards, Igor

Comment by Yurii Polenok [ 2021 Oct 28 ] 
15:53:10.311186 IP (tos 0x0, ttl 64, id 27796, offset 0, flags [DF], proto UDP (17), length 92)
    10.216.218.16.58773 > 10.216.216.167.161: [bad udp cksum 0xc8c1 -> 0x83d7!]  { SNMPv3 { F=r } { USM B=0 T=0 U="" } { ScopedPDU E= C="" { GetRequest(14) R=1480962533  } } } 
15:53:10.312489 IP (tos 0x0, ttl 63, id 36380, offset 0, flags [DF], proto UDP (17), length 134)
    10.216.216.167.161 > 10.216.218.16.58773: [udp sum ok]  { SNMPv3 { F= } { USM B=1 T=698243 U="" } { ScopedPDU E=_80_00_61_d9_03_00_00_00_00_00_00 C="" { Report(32) R=1480962533  .1.3.6.1.6.3.15.1.1.4.0=19418 } } } 
15:53:10.312606 IP (tos 0x0, ttl 64, id 27797, offset 0, flags [DF], proto UDP (17), length 166)
    10.216.218.16.58773 > 10.216.216.167.161: [bad udp cksum 0xc90b -> 0x602c!]  { SNMPv3 { F=apr } { USM B=1 T=5720469 U="nnm-switches" } { ScopedPDU [!scoped PDU]83_3b_7c_6c_68_a7_44_9f_73_13_d7_be_53_94_4a_93_21_c1_5e_0c_c0_dd_5c_df_ce_21_d7_a6_3b_3e_5e_b3_73_2f_98_96_35_f7_4e_c1_b9_2d_21_93_b1_f6_3c_af} } 
15:53:10.313084 IP (tos 0x0, ttl 63, id 36381, offset 0, flags [DF], proto UDP (17), length 155)
    10.216.216.167.161 > 10.216.218.16.58773: [udp sum ok]  { SNMPv3 { F=a } { USM B=1 T=698243 U="nnm-switches" } { ScopedPDU E=_80_00_61_d9_03_00_00_00_00_00_00 C="" { Report(29) R=0  .1.3.6.1.6.3.15.1.1.2.0=7506 } } } 
15:53:37.097891 IP (tos 0x0, ttl 64, id 41669, offset 0, flags [DF], proto UDP (17), length 92)
    10.216.218.16.11009 > 10.216.216.167.161: [bad udp cksum 0xc8c1 -> 0x85c6!]  { SNMPv3 { F=r } { USM B=0 T=0 U="" } { ScopedPDU E= C="" { GetRequest(14) R=1069165268  } } } 
15:53:37.099018 IP (tos 0x0, ttl 63, id 56618, offset 0, flags [DF], proto UDP (17), length 134)
    10.216.216.167.161 > 10.216.218.16.11009: [udp sum ok]  { SNMPv3 { F= } { USM B=1 T=698270 U="" } { ScopedPDU E=_80_00_61_d9_03_00_00_00_00_00_00 C="" { Report(32) R=1069165268  .1.3.6.1.6.3.15.1.1.4.0=19419 } } } 
15:53:37.099077 IP (tos 0x0, ttl 64, id 41670, offset 0, flags [DF], proto UDP (17), length 166)
    10.216.218.16.11009 > 10.216.216.167.161: [bad udp cksum 0xc90b -> 0xcefd!]  { SNMPv3 { F=apr } { USM B=1 T=5718648 U="nnm-switches" } { ScopedPDU [!scoped PDU]37_d5_f0_6c_98_57_62_5a_fa_db_f3_ac_96_45_38_38_11_a6_b3_e9_4e_9c_31_39_77_35_bd_1b_f8_ff_bf_89_2c_1a_ec_cf_58_ea_04_11_b3_b8_7c_59_13_0d_b8_7d} } 
15:53:37.099583 IP (tos 0x0, ttl 63, id 56619, offset 0, flags [DF], proto UDP (17), length 155)
    10.216.216.167.161 > 10.216.218.16.11009: [udp sum ok]  { SNMPv3 { F=a } { USM B=1 T=698270 U="nnm-switches" } { ScopedPDU E=_80_00_61_d9_03_00_00_00_00_00_00 C="" { Report(29) R=0  .1.3.6.1.6.3.15.1.1.2.0=7507 } } } 
15:53:40.342648 IP (tos 0x0, ttl 64, id 41862, offset 0, flags [DF], proto UDP (17), length 166)
    10.216.218.16.58773 > 10.216.216.167.161: [bad udp cksum 0xc90b -> 0x1ed6!]  { SNMPv3 { F=apr } { USM B=1 T=5720499 U="nnm-switches" } { ScopedPDU [!scoped PDU]fa_72_d2_76_7f_81_28_f4_31_6a_6f_75_03_79_9a_a8_27_17_f1_6c_b5_71_b1_6f_e6_31_9e_1d_12_b7_40_05_47_c8_32_67_7c_0d_99_24_92_4d_20_96_c4_8e_9a_78} } 
15:53:40.343620 IP (tos 0x0, ttl 63, id 57769, offset 0, flags [DF], proto UDP (17), length 155)
    10.216.216.167.161 > 10.216.218.16.58773: [udp sum ok]  { SNMPv3 { F=a } { USM B=1 T=698273 U="nnm-switches" } { ScopedPDU E=_80_00_61_d9_03_00_00_00_00_00_00 C="" { Report(29) R=0  .1.3.6.1.6.3.15.1.1.2.0=7508 } } }

Found that 3 devices have the same EngineID.
Related issues:
ZBX-2152
ZBX-8385
ZBXNEXT-2352

Comment by Igor Gorbach (Inactive) [ 2023 Jan 04 ]

SNMP v3 requires unique Engine Id for each device

https://snmp.com/products/securityanalyzer/demo/dupengid.html

Please, change the EngineID for the affected devices 

If the problem will be occur again after that - let us know

Generated at Fri May 23 07:32:22 EEST 2025 using Jira 9.12.4#9120004-sha1:625303b708afdb767e17cb2838290c41888e9ff0.