| 1 | = SNMP Hands - On = |
| 2 | |
| 3 | === Goals === |
| 4 | - Install and learn to use the SNMP commands |
| 5 | - Install vendor specific MIBs and use those with the SNMP commands |
| 6 | |
| 7 | === Notes === |
| 8 | - For below hands-on we will be using Ubuntu 20.04 version. |
| 9 | - If you are installing snmp client (manager) tools on a remote server/computer you will need to connect the server through a SSH connection. |
| 10 | |
| 11 | == Installing SNMP Client (Manager) tools == |
| 12 | |
| 13 | Connect to the server which will be used as the NMS (Network Management Station) and Open the Terminal program. |
| 14 | |
| 15 | Update your software package repository |
| 16 | {{{ |
| 17 | $ sudo apt-get update |
| 18 | }}} |
| 19 | This might take a few moments if everyone in class is doing this at the same moment. |
| 20 | |
| 21 | Install the net-snmp tools: |
| 22 | {{{ |
| 23 | $ sudo apt-get install snmp |
| 24 | $ sudo apt-get install snmp-mibs-downloader |
| 25 | }}} |
| 26 | The second of the two commands downloads the standard IETF and IANA SNMP MIBs which are not included by default. |
| 27 | |
| 28 | Now, edit the file /etc/snmp/snmp.conf: |
| 29 | {{{ |
| 30 | $ sudo vi /etc/snmp/snmp.conf |
| 31 | }}} |
| 32 | |
| 33 | Note: Here we are using '''vi''' editor. You can use any text editor you are familiar with |
| 34 | |
| 35 | Change this line: |
| 36 | {{{ |
| 37 | mibs : |
| 38 | }}} |
| 39 | |
| 40 | so that it looks like: |
| 41 | {{{ |
| 42 | # mibs : |
| 43 | }}} |
| 44 | |
| 45 | (You are "commenting out" the empty mibs statement, which was telling the snmp* tools not to automatically load the mibs in the /usr/share/mibs/ directory) |
| 46 | |
| 47 | === User specific SNMP configurations === |
| 48 | Now, in your home directory make a .snmp directory with file snmp.conf inside it, make it readable only be you, and add the credentials to it: |
| 49 | {{{ |
| 50 | $ cd |
| 51 | $ mkdir .snmp |
| 52 | $ chmod 700 .snmp/ |
| 53 | $ vi .snmp/snmp.conf |
| 54 | }}} |
| 55 | |
| 56 | |
| 57 | Put the following contents in the file: |
| 58 | {{{ |
| 59 | |
| 60 | defVersion 3 |
| 61 | |
| 62 | # SNMP v3 Configurations |
| 63 | defSecurityLevel authNoPriv |
| 64 | defSecurityName admin |
| 65 | defAuthPassphrase <class passowrd> |
| 66 | defAuthType SHA |
| 67 | |
| 68 | # SNMP v2c default community string |
| 69 | defCommunity <class passowrd> |
| 70 | |
| 71 | }}} |
| 72 | |
| 73 | == Configuration of SNMP Agent on Routers and Switches == |
| 74 | |
| 75 | ==== Cisco ==== |
| 76 | |
| 77 | connect to your router and go to configure mode. |
| 78 | {{{ |
| 79 | Router> enable |
| 80 | |
| 81 | Router# configure terminal |
| 82 | }}} |
| 83 | Now we need to add an Access Control List rule for SNMP access, turn on SNMP, assign a read-only SNMP community string as well as a SNMPv3 group and user and tell the router to maintain SNMP information across reboots. To do this we do: |
| 84 | {{{ |
| 85 | Router(config)# access-list 99 permit 192.248.6.0 255.255.255.0 |
| 86 | Router(config)# snmp-server community <class passowrd> ro 99 |
| 87 | Router(config)# snmp-server group ReadGroup v3 auth access 99 |
| 88 | Router(config)# snmp-server user admin ReadGroup v3 auth sha <Class Password> |
| 89 | Router(config)# snmp-server ifindex persist |
| 90 | Now let's exit and save this new configuration to the routers permanent config. |
| 91 | |
| 92 | Router(config)# exit |
| 93 | Router# write memory |
| 94 | Router# exit |
| 95 | }}} |
| 96 | |
| 97 | ==== HP ==== |
| 98 | Connect to the Router and go to config mode |
| 99 | {{{ |
| 100 | <Router> system-view |
| 101 | }}} |
| 102 | |
| 103 | Add the following configurations |
| 104 | {{{ |
| 105 | [Router]acl number 2000 |
| 106 | [Router-acl-basic-2000]rule 0 permit source 192.248.6.0 0.0.0.255 |
| 107 | [Router]snmp-agent |
| 108 | [Router]snmp-agent community read <class passowrd> |
| 109 | [Router]snmp-agent sys-info version all |
| 110 | [Router]snmp-agent group v3 ReadGroup authentication acl 2000 |
| 111 | [Router]snmp-agent usm-user v3 admin ReadGroup authentication-mode sha <class passowrd> |
| 112 | }}} |
| 113 | |
| 114 | == Testing SNMP == |
| 115 | Now we have both a SNMP Manager and SNMP Agent. To check that your SNMP installation works, run the snmpstatus command on the SNMP Manager host. |
| 116 | |
| 117 | {{{ |
| 118 | $ snmpstatus <IP_ADDRESS> |
| 119 | }}} |
| 120 | Note that you just used was the SNMPv3 because we set the default version as SNMPv3. Try again, adding "-v2c" as a parameter. Notice that the command automatically uses the community string in the snmp.conf file instead of the v3 user credentials. Try "-v1". |
| 121 | |
| 122 | To use the SNMP v2 or v1 we can add an option as below. Which will override the settings in the configuration file(/.snmp/snmp.conf). |
| 123 | |
| 124 | snmpstatus -v2c <IP_ADDRESS> |
| 125 | snmpstatus -v1 <IP_ADDRESS> |
| 126 | |
| 127 | Again we didn't want set Community string as it was set in the manager configuration file. |
| 128 | |
| 129 | For the Router, |
| 130 | {{{ |
| 131 | #snmpstatus <Router IP> |
| 132 | }}} |
| 133 | |
| 134 | For the Switch, |
| 135 | {{{ |
| 136 | #snmpstatus <Switch IP> |
| 137 | }}} |