| 1 | % Log Management Part 1: Using rsyslog |
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| 2 | % |
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| 3 | % Network Monitoring & Management |
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| 4 | |
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| 5 | # Notes |
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| 6 | |
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| 7 | * Commands preceded with "$" imply that you should execute the command as |
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| 8 | a general user - not as root. |
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| 9 | * Commands preceded with "#" imply that you should be working as root. |
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| 10 | * Commands with more specific command lines (e.g. "RTR-GW>" or "mysql>") |
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| 11 | imply that you are executing commands on remote equipment, or within |
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| 12 | another program. |
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| 13 | |
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| 14 | # Exercise |
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| 15 | |
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| 16 | The routers are able to send syslog messages to multiple destinations, |
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| 17 | so that 1 router can send messages to 4 or even 5 destinations. |
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| 18 | We therefore need to configure the router to send messages to each of |
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| 19 | the PCs in the group. |
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| 20 | |
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| 21 | ## Configure sending of syslog messages from your group's router |
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| 22 | |
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| 23 | Configure your virtual router to send syslog messages to every server |
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| 24 | in your group. |
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| 25 | |
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| 26 | Everyone in your group should log into your group's router and do the |
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| 27 | following (assuming you are already logging in on your virtual machine): |
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| 28 | |
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| 29 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 30 | $ ssh cisco@rtrX |
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| 31 | rtrX> enable |
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| 32 | rtrX# config terminal |
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| 33 | |
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| 34 | rtrX(config)# logging 10.10.X.Y |
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| 35 | |
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| 36 | ... where X.Y is the IP of your PC (group + number, example pc2 = 10.10.1.2). |
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| 37 | |
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| 38 | rtrX(config)# logging facility local0 |
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| 39 | rtrX(config)# logging userinfo |
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| 40 | rtrX(config)# exit |
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| 41 | rtrX# write memory |
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| 42 | rtrX# exit |
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| 43 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 44 | |
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| 45 | Now run `show logging` to see the summary of the log configuration. |
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| 46 | |
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| 47 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 48 | rtrX# show logging |
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| 49 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 50 | |
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| 51 | The other participants in your group will be doing the same thing, so you |
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| 52 | should not be surprised if you see other destinations as well in the output |
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| 53 | of "show logging" - Press SPACE to page through the output |
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| 54 | |
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| 55 | Logout from the router (exit): |
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| 56 | |
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| 57 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 58 | rtrX# exit |
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| 59 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 60 | |
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| 61 | That's it. The router should now be sending UDP SYSLOG packets to your PC |
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| 62 | on port 514. |
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| 63 | |
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| 64 | To verify this log in on your PC as user sysadm (if you have not already done so) |
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| 65 | and do the following: |
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| 66 | |
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| 67 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 68 | $ sudo bash |
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| 69 | # apt-get install tcpdump (if already installed dont worry) |
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| 70 | # tcpdump -s0 -n -i eth0 udp port 514 |
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| 71 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 72 | |
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| 73 | Then have one person in your group log back in on the router and do the |
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| 74 | following: |
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| 75 | |
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| 76 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 77 | $ ssh cisco@rtrX |
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| 78 | rtrX> enable |
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| 79 | rtrX# config terminal |
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| 80 | rtrX(config)# exit |
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| 81 | rtrX> exit |
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| 82 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 83 | |
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| 84 | You should see some output on your PC's screen from `tcpdump`. It should look |
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| 85 | something like: |
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| 86 | |
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| 87 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 88 | 11:20:24.942289 10.10.1.254.63515 > 10.10.1.1.514: SYSLOG local0.notice, length: 110 |
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| 89 | 11:20:24.944376 10.10.1.254.53407 > 10.10.1.1.514: SYSLOG local0.notice, length: 102 |
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| 90 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 91 | |
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| 92 | When you have seen this, hit Ctrl-C to exit tcpdump. |
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| 93 | |
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| 94 | Aside: tcpdump would also show you the *content* of the syslog messages if you |
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| 95 | add `-v` to the command line. To learn more about tcpdump type "man tcpdump" at |
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| 96 | the command line |
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| 97 | |
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| 98 | Now you can configure the logging software on your PC to receive this |
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| 99 | information and log it to a new set of files. |
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| 100 | |
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| 101 | |
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| 102 | ## Configure rsyslog |
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| 103 | |
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| 104 | Be sure you are logged in to your virtual machine and that you are the |
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| 105 | root user. |
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| 106 | |
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| 107 | Edit the file /etc/rsyslog.conf: |
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| 108 | |
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| 109 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 110 | # editor /etc/rsyslog.conf |
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| 111 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 112 | |
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| 113 | ...and find and un-comment the following lines |
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| 114 | (that is, remove the initial '#' only) |
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| 115 | |
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| 116 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 117 | #$ModLoad imudp |
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| 118 | #$UDPServerRun 514 |
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| 119 | |
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| 120 | change to: |
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| 121 | |
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| 122 | $ModLoad imudp |
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| 123 | $UDPServerRun 514 |
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| 124 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 125 | |
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| 126 | Then change this line: |
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| 127 | |
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| 128 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 129 | $PrivDropToGroup syslog |
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| 130 | |
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| 131 | change to: |
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| 132 | |
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| 133 | $PrivDropToGroup adm |
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| 134 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 135 | |
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| 136 | Then save the file and exit. |
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| 137 | |
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| 138 | Now, create a file named "/etc/rsyslog.d/30-routerlogs.conf" |
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| 139 | |
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| 140 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 141 | # editor /etc/rsyslog.d/30-routerlogs.conf |
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| 142 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 143 | |
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| 144 | ... and add the following lines (carefully COPY and PASTE): |
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| 145 | |
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| 146 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 147 | $template RouterLogs,"/var/log/network/%$YEAR%/%$MONTH%/%$DAY%/%HOSTNAME%-%$HOUR%.log" |
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| 148 | local0.* -?RouterLogs |
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| 149 | & ~ |
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| 150 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 151 | |
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| 152 | PLEASE double check (verify) that what you have pasted is the SAME as what |
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| 153 | is above. In particular, make sure that you are using TAB and not SPACE |
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| 154 | between "template" and "RouterLogs", and also between "local0.*" and |
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| 155 | "-?RouterLogs". |
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| 156 | |
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| 157 | If the above is not pasted correctly, it will NOT work. |
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| 158 | |
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| 159 | Save and exit, then do: |
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| 160 | |
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| 161 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 162 | # mkdir /var/log/network |
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| 163 | # chown syslog:adm /var/log/network |
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| 164 | # chmod g+w /var/log/network |
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| 165 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 166 | |
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| 167 | Restart rsyslog: |
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| 168 | |
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| 169 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 170 | # service rsyslog restart |
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| 171 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 172 | |
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| 173 | |
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| 174 | ## Test syslog |
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| 175 | |
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| 176 | To be sure there are some logging messages log back in to the router, and run |
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| 177 | some "config" commands, then logout. e.g. |
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| 178 | |
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| 179 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 180 | $ ssh cisco@rtrX |
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| 181 | rtrX> enable |
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| 182 | rtrX# config terminal |
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| 183 | rtrX(config)# exit |
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| 184 | rtrX> exit |
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| 185 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 186 | |
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| 187 | Be sure you log out of the router when you are finished. If too many people |
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| 188 | log in without logging out then others cannot gain access to the router. |
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| 189 | |
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| 190 | On your PC, See if messages are starting to appear under |
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| 191 | `/var/log/network/<year>/<month>/<day>/` |
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| 192 | |
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| 193 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 194 | $ cd /var/log/network |
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| 195 | $ ls |
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| 196 | $ cd 2013 |
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| 197 | $ ls |
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| 198 | ... this will show you the directory for the month |
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| 199 | ... cd into this directory |
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| 200 | $ ls |
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| 201 | ... repeat for the next level (the day of the month) |
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| 202 | $ ls |
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| 203 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 204 | |
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| 205 | Then use 'tail' to look at the log file(s) in this directory. The names |
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| 206 | are dynamic based on the sender and the host, so use the file that you see. |
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| 207 | It may be something like this: |
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| 208 | |
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| 209 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 210 | $ ls |
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| 211 | rtr8-16.log |
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| 212 | $ tail rtr8-16.log |
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| 213 | ... logging messages are shown ... |
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| 214 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 215 | |
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| 216 | ## Troubleshooting rsyslog |
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| 217 | |
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| 218 | If no files are appearing under the /var/log/network directory, then |
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| 219 | another command to try while logged into the router, in config mode, is |
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| 220 | to shutdown / no shutdown a Loopback interface, for example: |
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| 221 | |
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| 222 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 223 | $ ssh cisco@rtrX |
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| 224 | rtrX> enable |
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| 225 | rtrX# conf t |
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| 226 | rtrX(config)# interface Loopback 999 |
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| 227 | rtrX(config-if)# shutdown |
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| 228 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 229 | |
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| 230 | wait a few seconds |
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| 231 | |
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| 232 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 233 | rtrX(config-if)# no shutdown |
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| 234 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 235 | |
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| 236 | Then exit, and save the config ("write mem"): |
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| 237 | |
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| 238 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 239 | rtrX(config-if)# exit |
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| 240 | rtrX(config)# exit |
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| 241 | rtrX# write memory |
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| 242 | rtr1# exit |
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| 243 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 244 | |
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| 245 | Check the logs under `/var/log/network` |
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| 246 | |
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| 247 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 248 | # cd /var/log/network |
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| 249 | # ls |
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| 250 | ...follow the directory trail |
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| 251 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 252 | |
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| 253 | Still no logs? |
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| 254 | |
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| 255 | Try the following command to send a test log message locally: |
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| 256 | |
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| 257 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 258 | # logger -p local0.info "Hello World\!" |
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| 259 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 260 | |
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| 261 | If a file has not been created yet under `/var/log/network`, then check your |
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| 262 | configuration for typos. Don't forget to restart the rsyslog service each |
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| 263 | time you change the configuration. |
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| 264 | |
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| 265 | What other commands can you think of that you can run on the router (BE CAREFUL!) |
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| 266 | that will trigger syslog messages? You could try logging in on the router |
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| 267 | and typing an incorrect password for "enable". |
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| 268 | |
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| 269 | Be sure that you do an "ls" command in your logging directory to see if a new |
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| 270 | log file has been created at some point. |
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| 271 | |
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