Difference between revisions of "Wireless"

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(→‎netctl: update ArchLinux path; also add domain_suffix_match for extra security)
 
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=== Motivation ===
+
'''csc-wireless no longer exists. Members are advised to use eduroam or uw-unsecured.'''
  
The UW wireless network has a couple of major deficiencies:
 
  
# Weak signal in MC 3036, preventing some laptops from connecting
+
== Rosetta Stone ==
# Aggressive throttling of bandwidth, even to wired systems within the club office
+
See IST's page http://ist.uwaterloo.ca/cs/wireless.html for Windows and other devices.
  
The second point is quite important: UW's wireless will begin to throttle high bandwidth connections after a minute or two, decreasing bandwidth slowly from 1MB/s or more down to 100KB/s or less. Members can expect to sit in the office for an hour or more if they want to download many packages off of the CSC mirror.
+
The ca_cert line is only needed to verify the authenticity of the eduroam AP, and is otherwise not actually needed to connect to it. Keep in mind that removing it from your config means that you are technically vulnerable to someone creating a fake eduroam access point and using it to grab your Quest login, though honestly the chances of this ever happening on campus are extremely unlikely.
  
To work around this problem we have an access point in the Computer Science Club.
+
=== Linux ===
 +
If you don't wish to have your password floating around in a text file in /etc, then (at least for the wpa_supplicant based network managers) you may take the output of
 +
echo -n "hunter2" | iconv -t utf16le | openssl md4
 +
and replace the password line with
 +
password=hash:HASH_HERE
  
=== Configuration ===
 
  
* ESSID: csc-wireless
+
==== netctl ====
* AP: 00:19:5B:7D:DB:FE
+
Toss this into /etc/netctl/, making sure you edit identity and password. Replace wlan0 with the correct interface. Your correct interface can probably be seen in the output of
* Channel: 36 (5.18 GHz)
+
ip link
* Network: auth3net (129.96.192.0/23)
+
and probably is the one that starts with 'w'.
  
Clients must authenticate to the Network Authentication Appliance (NAA) as with uw-wireless, in accordance with [http://ist.uwaterloo.ca/ns/Admin/wireless/ this IST policy], points #2 through #4.
+
To connect, run sudo netctl start eduroam
  
=== Technical Overview ===
+
Connection='wireless'
 +
Interface=wlan0
 +
Security='wpa-configsection'
 +
IP='dhcp'
 +
WPAConfigSection=(
 +
    'identity="userid@uwaterloo.ca"'
 +
    'password="hunter2"'
 +
    'ssid="eduroam"'
 +
    'key_mgmt=WPA-EAP'
 +
    'eap=PEAP'
 +
    'ca_cert="/etc/ssl/certs/GlobalSign_Root_CA.pem"'
 +
    'domain_suffix_match="uwaterloo.ca"'
 +
)
  
The AP connects to acesulfame-potassium through a secondary NIC. On acesulfame-potassium, the following decision is made:
+
==== wicd ====
 +
Toss this into /etc/wicd/encryption/templates/ and edit /etc/wicd/encryption/templates/active to include a line with eduroam.
  
* IP packets destined for mathstudentorgsnet are brouted with SNAT to wireless-nat.csclub.uwaterloo.ca
+
name = Eduroam UW
* All other ethernet frames are bridged to auth3net
+
author = Steven She
 +
version = 1
 +
require username *Username password *Password
 +
-----
 +
ctrl_interface=/var/run/wpa_supplicant
 +
network={
 +
    ssid="$_ESSID"
 +
    scan_ssid="$_SCAN"
 +
    proto=RSN
 +
    key_mgmt=WPA-EAP
 +
    pairwise=CCMP
 +
    group=CCMP
 +
    eap=PEAP
 +
    identity="$_USERNAME"
 +
    password="$_PASSWORD"
 +
    ca_cert="/usr/share/ca-certificates/mozilla/GlobalSign_Root_CA.crt"
 +
    phase2="auth=MSCHAPV2"
 +
}
  
The network is identical to connection through uw-wireless in all respects, except for the special treatment of mathstudentorgs traffic. This special treatment bypasses uw-wireless throttling for machines on our network.
+
==== wpa_supplicant ====
 +
add this to a file in /etc/wpa_supplicant/.
  
=== Wireless Performance ===
+
network={
 +
    ssid="eduroam"
 +
    proto=RSN
 +
    key_mgmt=WPA-EAP
 +
    pairwise=CCMP
 +
    group=CCMP
 +
    eap=PEAP                                     
 +
    identity="userid@uwaterloo.ca"
 +
    password="hunter2"
 +
    ca_cert="/usr/share/ca-certificates/mozilla/GlobalSign_Root_CA.crt"
 +
    phase2="auth=MSCHAPV2"
 +
}
  
Tests were done on a 700MB Ubuntu ISO at an off peak time.
 
  
* uw-wireless
+
The previous setup has been [http://wiki.csclub.uwaterloo.ca/Wireless?oldid=2297 archived] for posterity.
** Initial speed: 1.3MB/s
 
** Final speed: 40KB/s
 
** Time: aborted after 27 minutes (got bored) with 67% remaining, ETA increased steadily throughout
 
  
  mike@freyr:/tmp$ time wget http://mirror.csclub.uwaterloo.ca/ubuntu-releases/7.10/ubuntu-7.10-desktop-i386.iso
+
[[Category:Systems]]
  --23:54:09--  http://mirror.csclub.uwaterloo.ca/ubuntu-releases/7.10/ubuntu-7.10-desktop-i386.iso
 
  Resolving mirror.csclub.uwaterloo.ca... 129.97.134.71
 
  Connecting to mirror.csclub.uwaterloo.ca|129.97.134.71|:80... connected.
 
  HTTP request sent, awaiting response... 302 Found
 
  Location: http://citric-acid.csclub.uwaterloo.ca/iso/ubuntu-gutsy/ubuntu-7.10-desktop-i386.iso [following]
 
  --23:54:09--  http://citric-acid.csclub.uwaterloo.ca/iso/ubuntu-gutsy/ubuntu-7.10-desktop-i386.iso
 
  Resolving citric-acid.csclub.uwaterloo.ca... 129.97.134.37
 
  Connecting to citric-acid.csclub.uwaterloo.ca|129.97.134.37|:80... connected.
 
  HTTP request sent, awaiting response... 200 OK
 
  Length: 729608192 (696M) [application/x-iso9660-image]
 
  Saving to: `ubuntu-7.10-desktop-i386.iso'
 
 
 
  11% [===>                                    ] 86,583,824  377K/s  eta 13m 34ss
 
  33% [========================>              ] 241,791,104 39.5K/s  eta 55m 48s
 
 
 
 
 
  real 27m40.165s
 
  user 0m1.008s
 
  sys 0m4.252s
 
 
 
* csc-wireless
 
** Initial speed: 1.83MB/s
 
** Final speed: 1.93MB/s
 
** Time: aborted after 6 minutes (ran out of disk) with 10% remaining, steady progress
 
 
 
  --00:27:07--  http://mirror.csclub.uwaterloo.ca/ubuntu-releases/7.10/ubuntu-7.10-desktop-i386.iso
 
  Resolving mirror.csclub.uwaterloo.ca... 129.97.134.71
 
  Connecting to mirror.csclub.uwaterloo.ca|129.97.134.71|:80... connected.
 
  HTTP request sent, awaiting response... 302 Found
 
  Location: http://citric-acid.csclub.uwaterloo.ca/iso/ubuntu-gutsy/ubuntu-7.10-desktop-i386.iso [following]
 
  --00:27:07--  http://citric-acid.csclub.uwaterloo.ca/iso/ubuntu-gutsy/ubuntu-7.10-desktop-i386.iso
 
  Resolving citric-acid.csclub.uwaterloo.ca... 129.97.134.37
 
  Connecting to citric-acid.csclub.uwaterloo.ca|129.97.134.37|:80... connected.
 
  HTTP request sent, awaiting response... 200 OK
 
  Length: 729608192 (696M) [application/x-iso9660-image]
 
  Saving to: `ubuntu-7.10-desktop-i386.iso'
 
 
 
  1% [>                                                                            ] 14,380,544  1.83M/s  eta 6m 29s
 
  33% [========================>                                                    ] 243,488,896 1.92M/s  eta 4m 46s
 
  65% [=================================================>                          ] 475,945,024 1.90M/s  eta 2m 21s
 
  91% [=====================================================================>      ] 670,317,304 1.93M/s  in 6m 5s 
 
 
 
 
 
  Cannot write to `ubuntu-7.10-desktop-i386.iso' (No space left on device).
 
 
 
  real 6m4.935s
 
  user 0m2.124s
 
  sys 0m11.161s
 
 
 
While these are quite unscientific, they do demonstrate the huge performance advantage of csc-wireless. I will repeat them without aborting, when I have time.
 
 
 
=== Detailed Configuration ===
 
 
 
==== Required Packages ====
 
 
 
To install required packages, type:
 
 
 
sudo aptitude install madwifi-source madwifi-tools wireless-tools vlan bridge-utils ebtables iptables iproute
 
 
 
Then build the modules for the installed kernel via:
 
 
 
sudo m-a a-i madwifi
 
 
 
==== Wireless Interface Configuration ====
 
 
 
First, configure the wireless interface. Use the following snippet:
 
 
 
auto ath0
 
iface ath0 inet manual
 
        pre-up wlanconfig ath0 destroy || true
 
        pre-up wlanconfig ath0 create wlandev wifi0 wlanmode ap
 
        post-down wlanconfig ath0 destroy
 
        wireless-mode master
 
        wireless-channel 36
 
        wireless-essid csc-wireless
 
 
 
Second, make a bridge between the wireless and auth3net. Use the following snippet, replacing IFACE by the interface connected to auth3net
 
 
auto br192
 
iface br192 inet manual
 
        bridge_ports IFACE ath0
 
        bridge_stp yes
 
        up brctl setbridgeprio br192 40000
 
        up ip route add 129.97.192.0/23 dev br192
 
 
 
==== Brouting Configuration ====
 
 
 
Additional setup is needed to enable fast communication between mathstudentorgsnet and auth3net. We take the minimally invasive approach of pulling packets destined for mathstudentorgsnet off the bridge and routing them, masquerading as wireless-nat.csclub.uwaterloo.ca. Masquerading is needed to ensure responses are routed correctly.
 
 
 
Finally, add 129.97.134.85 as a secondary IP address. You might do so by adding this snippet, replacing IFACE by the interface connected to mathstudentorgsnet:
 
 
 
auto IFACE:nat
 
iface IFACE:nat inet static
 
        address 129.97.134.85
 
        netmask 255.255.255.0
 
        network 129.97.134.0
 
 
 
Second, enable routing, by adding the following snippet to sysctl.conf:
 
 
 
net.ipv4.ip_forward=1
 
 
 
Third, configure ebtables to pull packets of the bridge. Type:
 
 
 
ebtables -t broute --flush
 
 
ebtables -t broute -A BROUTING -i ath0 \
 
    -p ipv4 --ip-src 129.97.192.0/23 --ip-dst 129.97.134.0/24 \
 
    -j redirect --redirect-target DROP
 
 
invoke-rc.d ebtables save
 
 
 
Finally, configure iptables to masquerade wireless users as wireless-nat.csclub. Type the following, replacing IFACE by the interface connected to mathstudentorgsnet:
 
 
 
iptables -t nat --flush
 
 
iptables -t nat -A POSTROUTING -o IFACE \
 
    -s 129.97.192.0/23 -d 129.97.134.0/24 \
 
    -j SNAT --to-source 129.97.134.85
 
 
invoke-rc.d iptables save
 
 
 
Ensure the appropriate routing table entry for auth3net exists--masquerading will not work without. It is included in the bridge configuration snippet above.
 
 
 
=== External Links ===
 
 
 
* [http://www.gentoo-wiki.com/HARDWARE_ar5212 Gentoo Guide]
 

Latest revision as of 20:58, 19 June 2018

csc-wireless no longer exists. Members are advised to use eduroam or uw-unsecured.


Rosetta Stone

See IST's page http://ist.uwaterloo.ca/cs/wireless.html for Windows and other devices.

The ca_cert line is only needed to verify the authenticity of the eduroam AP, and is otherwise not actually needed to connect to it. Keep in mind that removing it from your config means that you are technically vulnerable to someone creating a fake eduroam access point and using it to grab your Quest login, though honestly the chances of this ever happening on campus are extremely unlikely.

Linux

If you don't wish to have your password floating around in a text file in /etc, then (at least for the wpa_supplicant based network managers) you may take the output of

echo -n "hunter2" | iconv -t utf16le | openssl md4

and replace the password line with

password=hash:HASH_HERE


netctl

Toss this into /etc/netctl/, making sure you edit identity and password. Replace wlan0 with the correct interface. Your correct interface can probably be seen in the output of

ip link

and probably is the one that starts with 'w'.

To connect, run sudo netctl start eduroam

Connection='wireless'
Interface=wlan0
Security='wpa-configsection'
IP='dhcp'
WPAConfigSection=(
    'identity="userid@uwaterloo.ca"'
    'password="hunter2"'
    'ssid="eduroam"'
    'key_mgmt=WPA-EAP'
    'eap=PEAP'
    'ca_cert="/etc/ssl/certs/GlobalSign_Root_CA.pem"'
    'domain_suffix_match="uwaterloo.ca"'
)

wicd

Toss this into /etc/wicd/encryption/templates/ and edit /etc/wicd/encryption/templates/active to include a line with eduroam.

name = Eduroam UW
author = Steven She
version = 1
require username *Username password *Password
-----
ctrl_interface=/var/run/wpa_supplicant
network={
    ssid="$_ESSID"
    scan_ssid="$_SCAN"
    proto=RSN
    key_mgmt=WPA-EAP
    pairwise=CCMP
    group=CCMP
    eap=PEAP
    identity="$_USERNAME"
    password="$_PASSWORD"
    ca_cert="/usr/share/ca-certificates/mozilla/GlobalSign_Root_CA.crt"
    phase2="auth=MSCHAPV2"
}

wpa_supplicant

add this to a file in /etc/wpa_supplicant/.

network={
    ssid="eduroam"
    proto=RSN
    key_mgmt=WPA-EAP
    pairwise=CCMP
    group=CCMP
    eap=PEAP                                      
    identity="userid@uwaterloo.ca"
    password="hunter2"
    ca_cert="/usr/share/ca-certificates/mozilla/GlobalSign_Root_CA.crt"
    phase2="auth=MSCHAPV2"
}


The previous setup has been archived for posterity.