Installing Cacti for network monitoring


Short form install instructions for Debian-based Linuxes:

 apt-get install cacti

You may be prompted to install Apache and MySQL if you don’t have them installed.

You will prompted to select the webserver for which Cacti should be configured; select the appropriate one and then if MySQL is being installed, you’ll be prompted to set the MySQL ‘root’ user password.

The next prompt will be:

 The cacti package must have a database installed and configured before it can be used. 
 This can be optionally handled with dbconfig-common.
 Configure database for cacti with dbconfig-common?

Select yes and then enter the MySQL ‘root’ password when prompted. This will create the MySQL db and db user for cacti. You’ll be prompted for a password to set for that db user:

 Please provide a password for cacti to register with the database server. If left blank, a random password will be generated.
 MySQL application password for cacti:

Put a password in and then open your browser to http://$_the_server_you_installed_cacti_on/cacti ($_the_server_you_installed_cacti_on is either the FQDN or IP address of the server), select New Installation and click next:

Configure the options and paths, if any paths are not filled in, do a “which” on the command line of the server you’re installing on, and it should give you the full path.

$ which php /usr/bin/php

If it’s not installed, install it with apt-get.

Log in with the username admin and password admin and you will be prompted to change the password.

Short form install for Redhat-based distributions:

Install the required packages: yum install httpd httpd-devel mysql mysql-server php-mysql php-pear php-common php-gd php-devel php php-mbstring php-cli php-snmp net-snmp-utils net-snmp-libs rrdtool

MariaDB can be used instead of MySQL if you’ve already transitioned to it from mysql.

Start the www, db and snmp services:

 systemctl start httpd.service
 systemctl start mariadb.service
 systemctl start snmpd.service

and enable the services to autostart (chkconfig if you’re on older systems):

 systemctl enable httpd.service
 systemctl enable mariadb.service
 systemctl enable snmpd.service

Create a cacti database in your mysql:

 # mysql -u root -p -e 'create database cacti'

Create a cacti user with password ‘12345whatacoincidence’:

 # mysql -u root -p
 mysql> GRANT ALL ON cacti.* TO cacti@localhost IDENTIFIED BY '12345whatacoincidence';
 mysql> FLUSH privileges;
 mysql> \q

Installing cacti is made easier if you have the EPEL repo enabled, because then it’s just:

 yum install cacti

More info on EPEL repo:

The other (slightly more finicky) method is the tried and true compile-it-yourself method:

In any case, when you have it installed, you’ll want to import the cacti tables from cacti.sql, so first, find ‘cacti.sql’:

 # rpm -ql cacti | grep cacti.sql

and then (assuming it told you the file is in “/opt/cacti/cacti-0.8.7d/cacti.sql”,) import the file:

 # mysql -u cacti -p cacti < /opt/cacti/cacti-0.8.7d/cacti.sql

Then you will need to edit your /etc/cacti/db.php file, using your actual values:

 $database_type = "mysql";
 $database_default = "cacti";
 $database_hostname = "localhost";
 $database_username = "cacti";
 $database_password = "12345whatacoincidence";
 $database_port = "3306";

Update your httpd config (probably /etc/httpd/conf.d/cacti.conf) to allow traffic to your cacti site and then restart httpd (or setup .htpasswd for that directory)

Edit the file /etc/cron.d/cacti to uncomment the cacti line.

Finally you’re able to open your browser to http://$_the_server_you_installed_cacti_on/cacti ($_the_server_you_installed_cacti_on is either the FQDN or IP address of the server), select New Installation and click next:






Configure the options and paths, if any paths are not filled in, do a “which” on the command line of the server you’re installing on, and it should give you the full path. If it’s not installed, install it with yum:

$ which php /usr/bin/php

Log in with the username admin and password admin and you will be prompted to change the password.

Installing Cacti in Windows

If you have a WAMP install (because no one will give you a nickel to get a real computer), then you can still install cacti:


  1. login to cacti and set up your systems/switches/routers/firewalls to be monitored
  2. install and configure Network Weathermap and tell it to use your cacti (or mrtg etc) data so you can get a nice realtime(-ish) graph of your speeds and feeds.
  3. install and configure the thold plugin to alert you if the systems you’re monitoring are dropping below a particular threshold


Categories : HowTo  Networking

MACSec Redux


Good ol’ MACSec.

First, I posted a quick and dirty notes-for-myself, MACSec how-to for Juniper.

Then, I posted a similar MACSec howto for Cisco. So here’s a miscellany of different macsec implementations.

Let’s say you want to run your own router, because your Layer 8 & 9 specialists mandate it, here MACSec on linux.

Here’s a guy who did cisco-switch-to-cisco-switch macsec over an mpls link between a cisco and juniper router (because macsec works at layer 1 and thus you need to fake layer 1 via MLPS). So that’s a thing.

Here’s the Extreme Network’s MACSec implementation:

set macsec port mka enable tg.1.1
set macsec pre-shared-key port tg.1.1 ckn foo cak passphrase bar

HP switches macsec config

Brocade MACSec details and also a Brocade sample config of MACSec.

Network monitoring


I’m a big fan of Network Weathermap, so I thought this addition,, to add rack diagrams to NW, to be pretty great. It makes a great addition/companion to Cacti, about which I’ve written before. It can be kind of finicky to get everything working, but when you do, it’s pretty great.

Categories : Networking

DNS Fuckery


Cloudflare on how they’re mitigating reflection attacks. The tl;dr: optimized crypto (elliptic curve instead of RSA) for signing DNSSEC, refusing the ANY request and keeping responses with the constraints of a 512-byte UDP packet to mitigate amplification.

Detecting DNS Tunnelling via PacketBeat and Watcher and Elasticsearch

RandomDNS for randomizing use of DNSCrypt


Cisco MACSec Notes


A while back I did notes for MACSec on Juniper devices and here’s the Cisco equivalent of the 802.1AE (“MAC Sec”) implementation

  1. Your Cisco device needs to be running either an IP Base or IP Services image. MACSec is not happening otherwise.
  2. switch# cts credentials id trustsec password mypassword
  3. en then, conf t, then int Gig1/1 (or whatever)
  4. switch(config-if)# cts man
    % Enabling macsec on Gi1/1 (may take a few seconds)…
    switch(config-if-cts-manual)#no propagate sgt
    switch(config-if-cts-manual)#sap pmk abc123 mode-list gcm-encrypt
    switch(config-if-cts-manual)#no shut

Where abc123 is your shared secret. I believe this is analogous to Juniper’s cak. You can do this to aggregated links (“port-channel” for you Cisco folks) but you have to do it before you aggregate the trunks together into a single logical interface. E.g., do this on Gig1/1 and Gig1/2 and then create int Port-channel1 (channel-group 1 mode on in the interface config)


mode-list options are:

  • gcm-encrypt (authentication and encryption)
  • gmac (auth, no encrypt)
  • null (encapsulation only; no auth, no encryption)



  • to use 802.1x (cts dot1x) as opposed to cts man above, you have to enable 802.1x globally on each device.
  • if you select gcm as the sap mode, you need an additional macsec license from cisco (as well as the ipbase or ipservices image/license). if you select gcm without the license, the interface goes into link-down state.


show cts credentials

show macsec summary

show macsec interface

show authentication sessions interface gigabitethernet1/1


Additional reading:

The actual Cisco doc (this is for a cat4500 but translates well most places) (here’s one for 3750/3560)


Xwindows and Windows


Exceed is the best. Unfortunately, it is pricey:

Your other options are:

MobaXterm: in free and pay versions, pretty simple to install/setup and use.

Xming: free (old version) or pay (current version), also pretty simple to use.

Cygwin/X: complicated, kludgey and you should probably avoid it.

Tags :             

Automatically reverting configuration mistakes in JunOS and IOS


The old joke goes: I don’t make mistakes. I thought I did once, but I was wrong.

But here’s how to save yourself from mistakes when configuring a JunOS or IOS device:

JUNOS is easy, “commit check”, “commit confirmed” and the handy “rollback”. Frankly, if you’re on a JUNOS device, you should already know about these.

But how to do the same on IOS? Cisco’s configurations happen as soon as you hit enter on the config, right?

Here’s how:

  • The brute force method: “reload in 5”. Write your proposed changes in notepad++ (or notepad.exe if you insist). Login to the device that you’re going to change, and before you do any of your changes, run “reload in 5”. Then, make your changes. If you did something boneheaded that will disable the device or your connection to it, the device will reload from it’s start-config in 5 minutes, effectively erasing your running-config.

Of course, if this is a shared device, you’ve taken everyone offline for the time it takes the device to reboot. Or maybe you don’t want your config saved to start-config as a security measure*. So what do you do in order to prevent a reboot and still maintain the ability to revert a recently made change? Ah, you’ll be wanting the somewhat more sophisticated method 2:

  • First, turn on archive:

cisco-router#configure terminal

then configure a path for where it’ll be stored and save that:

cisco-router(config-archive)#path usbflash0:backup-config
cisco-router#write mem

Now you should be able to use “configure terminal revert time 5” which is IOS’ functional equivalent of JUNOS’ “commit confirmed 5”:

cisco-router#conf t revert time 5

Here it will tell you that your config is being backed up to where you told it to and that the config will be rolled back in 5 minutes. So make your changes:

cisco-router(config)#int gig 0/0

cisco-router(config-if)# shutdown

If everything is good, “configure confirm” to keep the change:

cisco-router(config-if)#configure confirm

For the truly worried, use both methods: “reload in 10” and “revert in 5”. If the revert doesn’t work, the reload will (this will still take down the router, but hey…)

Categories : HowTo  Networking  Security

Configuring cacti for 1-minute polling


Trickier than it sounds, just because there’s lots of moving parts. Here is a handy guide that gets all the notes right:

Categories : HowTo

Juniper MACSec Notes


MACSec is kind of neat (TL;DR for the impatient: layer-1 crypto on links).

Media Access Control Security (MACsec) is an industry-standard security technology that provides secure communication for all traffic on Ethernet links. MACsec provides point-to-point security on Ethernet links between directly connected nodes and is capable of identifying and preventing most security threats, including denial of service, intrusion, man-in-the-middle, masquerading, passive wiretapping, and playback attacks. MACsec is standardized in IEEE 802.1AE.

MACsec allows you to secure an Ethernet link for almost all traffic, including frames from the Link Layer Discovery Protocol (LLDP), Link Aggregation Control Protocol (LACP), Dynamic Host Configuration Protocol (DHCP), Address Resolution Protocol (ARP), and other protocols that are not typically secured on an Ethernet link because of limitations with other security solutions. MACsec can be used in combination with other security protocols such as IP Security (IPsec) and Secure Sockets Layer (SSL) to provide end-to-end network security.

CLI config:

#create an association:
set security macsec connectivity-association ca1

#choose a mode (static cak recommended — see here for why)
set security macsec connectivity-association ca1 security-mode static-cak

#ckn needs to be a 64-digit number in hex, but any empty space is padded w/ 0’s
set security macsec connectivity-association ca1 pre-shared-key ckn deadbeef99

#cak needs to be a 32-digit number in hex, but any empty space is padded w/ 0’s
set security macsec connectivity-association ca1 pre-shared-key cak deadbeef11

# set to 255 to make it “less likely” to be chosen as key server, 0 for “more likely”
set security macsec connectivity-association ca1 mka key-server-priority 0

# set to 6000 for high-traffic environment. default to 2000.
set security macsec connectivity-association ca1 mka transmit-interval 6000

#this leaves headers unencrypted for troubleshooting, set to 0 for full encryption, set to 50 for unencrypted ipv6 headers
set security macsec connectivity-association ca1 offset 30

# replay protection, set to 0 to enforce all packets coming in order
set security macsec connectivity-association ca1 replay-protect replay-window-size 5

# exclude a protocol
set exclude-protocol lldp

#enable macsec
set security macsec interfaces xe-0/1/0 connectivity-association ca1

show security macsec statistics interface xe-0/1/0 detail

additional reading:
(Cisco version:


There’s a Cisco version of this here:

Categories : HowTo  Networking  Security

Port forwarding in Junos


First, define your objects:

set security zones security-zone Internal address-book address TSserver1

and whatever service you need to:

set applications application MS-RDP protocol tcp destination-port 3389

and your destination nat pool:

set security nat destination pool dnat-192_168_1_151 address

set security nat destination pool dnat-192_168_1_151 address port 3389

and your NAT policy:

Define the NAT policy is configured which specifies the NAT pool that the traffic should be translated to.

set security nat destination rule-set dst-nat from zone Internet

set security nat destination rule-set dst-nat rule rule1 match destination-address

set security nat destination rule-set dst-nat rule rule1 match destination-port 63389

set security nat destination rule-set dst-nat rule rule1 then destination-nat pool dnat-192_168_1_151

and lastly, your security policy to allow the traffic through:

Use the internal (real) IP address and port of the server — the security/firewall aspect happens after the “networking” aspect of the connection:

set security policies from-zone untrust to-zone trust policy Internet_to_Internal_RDP match source-address any destination-address TSserver1 application MS-RDP
set security policies from-zone untrust to-zone trust policy Internet_to_Internal_RDP then permit

Once you’ve commited the change, an RDP connection to will get translated to

Categories : HowTo