I wanted to stress-test multilayer switch Juniper EX 4200 and its routing engine. Somehow. I wanted to simulate a number of BGP routes and how will switch react. Importing and filtering BGP routes to Adj-RIB-In table and then to routing table could be stressfull for device and this could lead to 100% cpu usage and for example OSPF adjacency flapping. Most of work in this blog is done by a route generator script. You could also use a spreadsheet editor (Excel) and then edit exported text to create routes in Quagga configuration file.
What do you need?
- router (EX4200 with a advanced license. But don't worry. BGP on EX4200 should work even without license. At least it used to work on older releases. It yelds message to console during commit and regularry to syslog)
- standard Linux or Ubuntu PC with NIC and Quagga
- ethernet cable :-)
Juniper EX 4200 specifications [2]
IPv4 Unicast routes: 16,000
Install and configure Quagga on a Ubuntu PC
# apt-get install quagga
Change Ubuntu IP addresses
# ifconfig eth0 192.0.2.1/24
Edit Quagga configuration file ...
# nano /etc/quagga/daemons
... and you should run at least these two Quagga daemons
zebra=yes
bgp=yes
How to generate many routes
I used script from this site V. Glinsky[1] blog.
Change these two lines in that script:
my $router_id="192.0.2.1"; #bgp router-id
my $remote_ip="192.0.2.2"; #BGP neighbor ip address
Leave other values unchanged. It is going to generate 300,000 routes. Much more than 16,000. Let's say we are all right with AS numbers. Ubuntu AS65099, Juniper AS65001. Actually I generated 599999 routes in my example.
Copy generated bgpd.conf file to a directory /etc/quagga/.Here is how bgpd.conf should look
hostname quagga-host
password zebra
enable password zebra
line vty
router bgp 65099
bgp router-id 192.0.2.1
neighbor 192.0.2.2 remote-as 65001
network 70.0.0.0/24
network 70.0.1.0/24
network 70.0.2.0/24
network 70.0.3.0/24
Run Quagga
# /etc/init.d/quagga restart
Configure Juniper BGP protocol and interface
root@ex4200> show configuration protocols bgp
local-as 65001;
group bgp-test {
type external;
peer-as 65099;
neighbor 192.0.2.1;
}
root@ex4200> show configuration interfaces ge-0/0/0
unit 0 {
family inet {
address 192.0.2.2/24;
}
root@ex4200> show configuration routing-options
router-id 192.0.2.2;
autonomous-system 65001;
There is a warning during commit. You should have a license. Don't worry, it's OK for now. It will work even without it.
{master:0}[edit]
root@ex4200# commit
[edit protocols]
'bgp'
warning: requires 'bgp' license
configuration check succeeds
commit complete
Connect two devices with ethernet cable and observe results
Juniper EX 4200:
root@ex4200> show bgp summary
Groups: 1 Peers: 1 Down peers: 0
Table Tot Paths Act Paths Suppressed History Damp State Pending
inet.0
16372 16372 0 0 0 0
Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
192.0.2.1 65099 299 4 0 0 28 16372/16372/16372/0 0/0/0/0
BGP neighbor adjacency status is Established. Highlighted is number of accepted routes in a Adj-Rib-In table. We don't use any import policy.
root@ex4200> show route
inet.0: 16384 destinations, 16384 routes (16384 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
2.0.0.0/24 *[BGP/170] 00:00:39, MED 0, localpref 100
AS path: 65099 I, validation-state: unverified
> to 192.0.2.1 via ge-0/0/0.0
2.0.1.0/24 *[BGP/170] 00:00:39, MED 0, localpref 100
AS path: 65099 I, validation-state: unverified
> to 192.0.2.1 via ge-0/0/0.0
2.0.2.0/24 *[BGP/170] 00:00:39, MED 0, localpref 100
AS path: 65099 I, validation-state: unverified
> to 192.0.2.1 via ge-0/0/0.0
2.0.3.0/24 *[BGP/170] 00:00:39, MED 0, localpref 100
AS path: 65099 I, validation-state: unverified
> to 192.0.2.1 via ge-0/0/0.0
2.0.4.0/24 *[BGP/170] 00:00:39, MED 0, localpref 100
AS path: 65099 I, validation-state: unverified
> to 192.0.2.1 via ge-0/0/0.0
2.0.5.0/24 *[BGP/170] 00:00:39, MED 0, localpref 100
AS path: 65099 I, validation-state: unverified
> to 192.0.2.1 via ge-0/0/0.0
2.0.6.0/24 *[BGP/170] 00:00:39, MED 0, localpref 100
---(more)---
Highlighted number is number of active routes in routing table.
root@ex4200> show chassis routing-engine
Routing Engine status:
Slot 0:
Current state Master
Temperature 34 degrees C / 93 degrees F
CPU temperature 34 degrees C / 93 degrees F
DRAM 1024 MB
Memory utilization 44 percent
CPU utilization:
User 23 percent
Background 0 percent
Kernel 34 percent
Interrupt 0 percent
Idle 42 percent
Model EX4200-24F
Serial ID BR0210217636
Start time 2013-01-19 19:28:27 UTC
Uptime 31 minutes, 9 seconds
Last reboot reason 0x2:watchdog
Load averages: 1 minute 5 minute 15 minute
0.45 0.15 0.10
CPU utilization is a bit higher right after establishing adjacency and receiving routes.
You could also use command
> show system processes extended
to see how rpd process is using CPU [3].
Connect to Quagga and show bgp config
root@bt:~# telnet localhost 2605
Trying ::1...
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Hello, this is Quagga (version 0.99.15).
Copyright 1996-2005 Kunihiro Ishiguro, et al.
User Access Verification
Password: (password is zebra or quagga)
quagga-host>
quagga-host> show ip bgp summary
BGP router identifier 192.0.2.1, local AS number 65099
RIB entries 599999, using 37 MiB of memory
Peers 1, using 2520 bytes of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
192.0.2.2 4 65001 5 304 0 0 0 00:02:00 0
Total number of neighbors 1
quagga-host> show ip bgp neighbors
BGP neighbor is 192.0.2.2, remote AS 65001, local AS 65099, external link
BGP version 4, remote router ID 192.0.2.2
BGP state = Established, up for 00:02:05
Last read 00:00:19, hold time is 90, keepalive interval is 30 seconds
Neighbor capabilities:
4 Byte AS: advertised and received
Route refresh: advertised and received(old & new)
Address family IPv4 Unicast: advertised and received
Graceful Restart Capabilty: received
Remote Restart timer is 120 seconds
Address families by peer:
none
Graceful restart informations:
End-of-RIB send: IPv4 Unicast
End-of-RIB received:
Message statistics:
Inq depth is 0
Outq depth is 0
Sent Rcvd
Opens: 1 0
Notifications: 0 0
Updates: 298 0
Keepalives: 6 5
Route Refresh: 0 0
Capability: 0 0
Total: 305 5
Minimum time between advertisement runs is 30 seconds
For address family: IPv4 Unicast
Community attribute sent to this neighbor(both)
0 accepted prefixes
Connections established 1; dropped 0
Last reset never
Local host: 192.0.2.1, Local port: 179
Foreign host: 192.0.2.2, Foreign port: 60656
Nexthop: 192.0.2.1
Nexthop global: ::
Nexthop local: ::
BGP connection: non shared network
Read thread: on Write thread: off
Session is established. 599999 routes loaded from config file.
Other ways to BGP routes generation
Nice guide on how to generate routes from real world bgp routes dump:
http://evilrouters.net/2009/08/21/getting-bgp-routes-into-dynamips-with-video/
How to mitigate this 'attack'?
There is a command
References:
[1] http://blog.glinskiy.com/2009/10/how-to-generate-lots-of-bgp-routes.html
[2] http://www.juniper.net/us/en/products-services/switching/ex-series/ex4200/#specifications
[3] http://www.juniper.net/techpubs/en_US/junos9.6/information-products/topic-collections/nog-baseline/routing-engine--memory-introduction.html
