sonic-buildimage/dockers/docker-snmp/snmpd.conf.j2
SuvarnaMeenakshi 803c71c86a
[SNMP][IPv6]: Fix to use link local IPv6 address as snmp agentAddress (#16013)
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#### Why I did it
fixes: https://github.com/sonic-net/sonic-buildimage/issues/16001
Caused by: https://github.com/sonic-net/sonic-buildimage/pull/15487

The above PR introduced change to use Management and Loopback Ipv4 and ipv6 addresses as snmpagent address in snmpd.conf file.
With this change, if Link local IP address is configured as management or Loopback IPv6 address, then snmpd tries to open socket on that ipv6 address and fails with the below error:
```
Error opening specified endpoint "udp6:[fe80::5054:ff:fe6f:16f0]:161"
Server Exiting with code 1
```
From RFC4007, if we need to specify non-global ipv6 address without ambiguity, we need to use zone id along with the ipv6 address: <address>%<zone_id>
Reference: https://datatracker.ietf.org/doc/html/rfc4007

##### Work item tracking
- Microsoft ADO **(number only)**:

#### How I did it
Modify snmpd.conf file to use the %zone_id representation for ipv6 address.
#### How to verify it
In VS testbed, modify config_db to use link local ipv6 address as management address:
    "MGMT_INTERFACE": {
        "eth0|10.250.0.101/24": {
            "forced_mgmt_routes": [
                "172.17.0.1/24"
            ],
            "gwaddr": "10.250.0.1"
        },
        "eth0|fe80::5054:ff:fe6f:16f0/64": {
            "gwaddr": "fe80::1"
        }
    },

Execute config_reload after the above change.
snmpd comes up and check if snmpd is listening on ipv4 and ipv6 addresses:
```
admin@vlab-01:~$ sudo netstat -tulnp | grep 161
tcp        0      0 127.0.0.1:3161          0.0.0.0:*               LISTEN      274060/snmpd        
udp        0      0 10.1.0.32:161           0.0.0.0:*                           274060/snmpd        
udp        0      0 10.250.0.101:161        0.0.0.0:*                           274060/snmpd        
udp6       0      0 fc00:1::32:161          :::*                                274060/snmpd        
udp6       0      0 fe80::5054:ff:fe6f::161 :::*                                274060/snmpd      -- Link local 
 
admin@vlab-01:~$ sudo ifconfig eth0
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.250.0.101  netmask 255.255.255.0  broadcast 10.250.0.255
        inet6 fe80::5054:ff:fe6f:16f0  prefixlen 64  scopeid 0x20<link>
        ether 52:54:00:6f:16:f0  txqueuelen 1000  (Ethernet)
        RX packets 36384  bytes 22878123 (21.8 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 261265  bytes 46585948 (44.4 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

admin@vlab-01:~$ docker exec -it snmp snmpget -v2c -c public fe80::5054:ff:fe6f:16f0 1.3.6.1.2.1.1.1.0
iso.3.6.1.2.1.1.1.0 = STRING: "SONiC Software Version: SONiC.master.327516-04a6031b2 - HwSku: Force10-S6000 - Distribution: Debian 11.7 - Kernel: 5.10.0-18-2-amd64"
```
Logs from snmpd:
```
Turning on AgentX master support.
NET-SNMP version 5.9
Connection from UDP/IPv6: [fe80::5054:ff:fe6f:16f0%eth0]:44308
```
Ran test_snmp_loopback test to check if loopback ipv4 and ipv6 works:
```
./run_tests.sh -n vms-kvm-t0 -d vlab-01 -c snmp/test_snmp_loopback.py  -f vtestbed.yaml -i ../ansible/veos_vtb -e "--skip_sanity --disable_loganalyzer" -u
=== Running tests in groups ===
Running: pytest snmp/test_snmp_loopback.py --inventory ../ansible/veos_vtb --host-pattern vlab-01 --testbed vms-kvm-t0 --testbed_file vtestbed.yaml --log-cli-level warning --log-file-level debug --kube_master unset --showlocals --assert plain --show-capture no -rav --allow_recover --ignore=ptftests --ignore=acstests --ignore=saitests --ignore=scripts --ignore=k8s --ignore=sai_qualify --junit-xml=logs/tr.xml --log-file=logs/test.log --skip_sanity --disable_loganalyzer
..                                                                        

snmp/test_snmp_loopback.py::test_snmp_loopback[vlab-01] PASSED 
```
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2023-08-08 14:47:33 -07:00

237 lines
8.2 KiB
Django/Jinja

###############################################################################
# Managed by sonic-config-engine
###############################################################################
#
# EXAMPLE.conf:
# An example configuration file for configuring the Net-SNMP agent ('snmpd')
# See the 'snmpd.conf(5)' man page for details
#
# Some entries are deliberately commented out, and will need to be explicitly activated
#
###############################################################################
#
# AGENT BEHAVIOUR
#
# Listen for connections on all ip addresses, including eth0, ipv4 lo for multi-asic platform
# Listen on managment and loopback0 ips for single asic platform
#
{% macro protocol(ip_addr) %}
{%- if ip_addr|ipv6 -%}
{{ 'udp6' }}
{%- else -%}
{{ 'udp' }}
{%- endif -%}
{% endmacro %}
{% if SNMP_AGENT_ADDRESS_CONFIG %}
{% for (agentip, port, vrf) in SNMP_AGENT_ADDRESS_CONFIG %}
agentAddress {{ protocol(agentip) }}:[{{ agentip }}]{% if port %}:{{ port }}{% endif %}{% if vrf %}%{{ vrf }}{% endif %}{{ "" }}
{% endfor %}
{% elif NAMESPACE_COUNT is not defined or NAMESPACE_COUNT|int <= 1 %}
{% if MGMT_INTERFACE is defined %}
{% for intf, ip in MGMT_INTERFACE %}
{% set agentip = ip.split('/')[0]|lower %}
{% set zoneid = '' %}
# Use interface as zoneid for link local ipv6
{% if agentip.startswith('fe80') %}
{% set zoneid = '%' + intf %}
{% endif %}
agentAddress {{ protocol(agentip) }}:[{{ agentip }}{{ zoneid }}]:161
{% endfor %}
{% endif %}
{% if LOOPBACK_INTERFACE is defined %}
{% for lo in LOOPBACK_INTERFACE %}
{% if lo | length == 2 %}
{% set intf = lo[0] %}
{% set agentip = lo[1].split('/')[0]|lower %}
{% set zoneid = '' %}
# Use interface as zoneid for link local ipv6
{% if agentip.startswith('fe80') %}
{% set zoneid = '%' + intf %}
{% endif %}
agentAddress {{ protocol(agentip) }}:[{{ agentip }}{{ zoneid }}]:161
{% endif %}
{% endfor %}
{% endif %}
{% else %}
agentAddress udp:161
agentAddress udp6:161
{% endif %}
###############################################################################
#
# ACCESS CONTROL
#
# system + hrSystem groups only
view systemonly included .1.3.6.1.2.1.1
view systemonly included .1.3.6.1.2.1.25.1
# Default access to basic system info
{% if SNMP_COMMUNITY is defined %}
{% for community in SNMP_COMMUNITY %}
{% if SNMP_COMMUNITY[community]['TYPE'] == 'RO' %}
rocommunity {{ community }}
rocommunity6 {{ community }}
{% endif %}
{% endfor %}
{% endif %}
{% if SNMP_COMMUNITY is defined %}
{% for community in SNMP_COMMUNITY %}
{% if SNMP_COMMUNITY[community]['TYPE'] == 'RW' %}
rwcommunity {{ community }}
rwcommunity6 {{ community }}
{% endif %}
{% endfor %}
{% endif %}
{% if SNMP_USER is defined %}
{% for user in SNMP_USER %}
{% if SNMP_USER[user]['SNMP_USER_PERMISSION'] == 'RO' %}
rouser {{ user }} {{ SNMP_USER[user]['SNMP_USER_TYPE'] }}
CreateUser {{ user }} {{ SNMP_USER[user]['SNMP_USER_AUTH_TYPE'] }} {{ SNMP_USER[user]['SNMP_USER_AUTH_PASSWORD'] }} {{ SNMP_USER[user]['SNMP_USER_ENCRYPTION_TYPE'] }} {{ SNMP_USER[user]['SNMP_USER_ENCRYPTION_PASSWORD'] }}
{% elif SNMP_USER[user]['SNMP_USER_PERMISSION'] == 'RW' %}
rwuser {{ user }} {{ SNMP_USER[user]['SNMP_USER_TYPE'] }}
CreateUser {{ user }} {{ SNMP_USER[user]['SNMP_USER_AUTH_TYPE'] }} {{ SNMP_USER[user]['SNMP_USER_AUTH_PASSWORD'] }} {{ SNMP_USER[user]['SNMP_USER_ENCRYPTION_TYPE'] }} {{ SNMP_USER[user]['SNMP_USER_ENCRYPTION_PASSWORD'] }}
{% endif %}
{% endfor %}
{% else %}
{% endif %}
###############################################################################
#
# SYSTEM INFORMATION
#
# Note that setting these values here, results in the corresponding MIB objects being 'read-only'
# See snmpd.conf(5) for more details
{% if SNMP is defined and SNMP.LOCATION is defined %}
sysLocation {{ SNMP.LOCATION.Location }}
{% else %}
sysLocation public
{% endif %}
{% if SNMP is defined and SNMP.CONTACT is defined %}
sysContact {{ SNMP.CONTACT.keys() | first }} {{ SNMP.CONTACT.values() | first }}
{% else %}
sysContact Azure Cloud Switch vteam <linuxnetdev@microsoft.com>
{% endif %}
# Application + End-to-End layers
sysServices 72
#
# Process Monitoring
#
# todo: should we enable snmp based monitoring of sswsyncd and other processes?
# At least one 'sendmail' process, but no more than 10
#proc sendmail 10 1
# Walk the UCD-SNMP-MIB::prTable to see the resulting output
# Note that this table will be empty if there are no "proc" entries in the snmpd.conf file
#
# Disk Monitoring
#
# 10MBs required on root disk, 5% free on /var, 10% free on all other disks
disk / 10000
disk /var 5%
includeAllDisks 10%
# Walk the UCD-SNMP-MIB::dskTable to see the resulting output
# Note that this table will be empty if there are no "disk" entries in the snmpd.conf file
#
# System Load
#
# Unacceptable 1-, 5-, and 15-minute load averages
load 12 10 5
# Walk the UCD-SNMP-MIB::laTable to see the resulting output
# Note that this table *will* be populated, even without a "load" entry in the snmpd.conf file
###############################################################################
#
# ACTIVE MONITORING
#
# Note: disabled snmp traps due to side effect of causing snmpd to listen on all ports (0.0.0.0)
#
# send SNMPv1 traps
{% if SNMP_TRAP_CONFIG and SNMP_TRAP_CONFIG['v1TrapDest'] %}
{% set v1SnmpTrapIp = SNMP_TRAP_CONFIG['v1TrapDest']['DestIp'] %}
{% set v1SnmpTrapPort = SNMP_TRAP_CONFIG['v1TrapDest']['DestPort'] %}
{% set v1SnmpTrapVrf = SNMP_TRAP_CONFIG['v1TrapDest']['vrf'] %}
{% set v1SnmpTrapComm = SNMP_TRAP_CONFIG['v1TrapDest']['Community'] %}
trapsink {{ v1SnmpTrapIp }}:{{ v1SnmpTrapPort }}{% if v1SnmpTrapVrf != 'None' %}%{{ v1SnmpTrapVrf }}{% endif %} {{ v1SnmpTrapComm }}{{ "" }}
{% else %}
#trapsink localhost public
{% endif %}
# send SNMPv2c traps
{% if SNMP_TRAP_CONFIG and SNMP_TRAP_CONFIG['v2TrapDest'] %}
{% set v2SnmpTrapIp = SNMP_TRAP_CONFIG['v2TrapDest']['DestIp'] %}
{% set v2SnmpTrapPort = SNMP_TRAP_CONFIG['v2TrapDest']['DestPort'] %}
{% set v2SnmpTrapVrf = SNMP_TRAP_CONFIG['v2TrapDest']['vrf'] %}
{% set v2SnmpTrapComm = SNMP_TRAP_CONFIG['v2TrapDest']['Community'] %}
trap2sink {{ v2SnmpTrapIp }}:{{ v2SnmpTrapPort }}{% if v2SnmpTrapVrf != 'None' %}%{{ v2SnmpTrapVrf }}{% endif %} {{ v2SnmpTrapComm }}{{ "" }}
{% else %}
#trap2sink localhost public
{% endif %}
# send SNMPv2c INFORMs
{% if SNMP_TRAP_CONFIG and SNMP_TRAP_CONFIG['v3TrapDest'] %}
{% set v3SnmpTrapIp = SNMP_TRAP_CONFIG['v3TrapDest']['DestIp'] %}
{% set v3SnmpTrapPort = SNMP_TRAP_CONFIG['v3TrapDest']['DestPort'] %}
{% set v3SnmpTrapVrf = SNMP_TRAP_CONFIG['v3TrapDest']['vrf'] %}
{% set v3SnmpTrapComm = SNMP_TRAP_CONFIG['v3TrapDest']['Community'] %}
trapsink {{ v3SnmpTrapIp }}:{{ v3SnmpTrapPort }}{% if v3SnmpTrapVrf != 'None' %}%{{ v3SnmpTrapVrf }}{% endif %} {{ v3SnmpTrapComm }}{{ "" }}
{% else %}
#informsink localhost public
{% endif %}
# Note that you typically only want *one* of these three lines
# Uncommenting two (or all three) will result in multiple copies of each notification.
#
# Event MIB - automatically generate alerts
#
# Remember to activate the 'createUser' lines above
#iquerySecName internalUser
#rouser internalUser
# generate traps on UCD error conditions
#defaultMonitors yes
#note, this release of snmpd does not support linkUpDownNotifications
# generate traps on linkUp/Down
#linkUpDownNotifications yes
#
# AgentX Sub-agents
#
# Run as an AgentX master agent
master agentx
# internal socket to allow extension to other docker containers
# Currently the other container using this is docker-fpm-frr
# make sure this line matches bgp:/etc/snmp/frr.conf
# please see testing procedure in the same file to verify this works
# to verify the SNMP docker side look for the following string in the log file:
# INFO snmp-subagent [ax_interface] INFO: Using agentx socket type tcp with path tcp:localhost:3161
# INFO supervisord snmp-subagent INFO:ax_interface:Using agentx socket type tcp with path tcp:localhost:3161
agentxsocket tcp:localhost:3161
#
# SysDescription pass-through
#
pass -p 10 .1.3.6.1.2.1.1.1 /usr/share/snmp/sysDescr_pass.py