Increasing maximum # of IP addresses handed out by proxy server
I'm having trouble with a Ubuntu-based proxy server that's running Squid and DansGuardian. The server is used for content-filtering a guest wireless network.
The system was set up by a consultant who is no longer available, and I'm trying to troubleshoot an issue. My Linux skills and my networking skills are fairly basic, to say the least.
Here is the problem: After the server runs for three or four days, new devices are no longer able to connect to the wireless network. The devices seem unable to get an IP address. My suspicion is that there is a limit to the number of addresses (maybe 50?) that the server gives out.
Based on the very sparse documentation that was provided by the networking consultant, I know that routing is turned on by executing this command at boot time:
echo 1 > /proc/sys/net/ipv4/ip_forw
Is there a config file somewhere that I can edit to determine (and then change) the maximum number of IP addresses that the server can hand out? As I said, I don't have much experience in this area, and I wasn't able to answer the question via running Google searches.
Thanks in advance for any guidance.
The system was set up by a consultant who is no longer available, and I'm trying to troubleshoot an issue. My Linux skills and my networking skills are fairly basic, to say the least.
Here is the problem: After the server runs for three or four days, new devices are no longer able to connect to the wireless network. The devices seem unable to get an IP address. My suspicion is that there is a limit to the number of addresses (maybe 50?) that the server gives out.
Based on the very sparse documentation that was provided by the networking consultant, I know that routing is turned on by executing this command at boot time:
echo 1 > /proc/sys/net/ipv4/ip_forw
Is there a config file somewhere that I can edit to determine (and then change) the maximum number of IP addresses that the server can hand out? As I said, I don't have much experience in this area, and I wasn't able to answer the question via running Google searches.
Thanks in advance for any guidance.
ASKER
@southpau1 -- the page you referenced talks about setting a limit for simultaneous web connections from a single client. I don't think that that's the issue in my case.
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ASKER
@Savone, I think you may have given me the clue I needed. I did some more poking around, and I think that the server is running udhcpd. There is a promising-looking config file at /etc/udhcpd.conf.
Unfortunately, it's the end of the day right now, and I have to go home. I will take a closer look at it tomorrow.
Unfortunately, it's the end of the day right now, and I have to go home. I will take a closer look at it tomorrow.
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ASKER
Savone, I've attached the udhcpd.conf file. Can I ask you a few questions about it?
I assume that the block of dynamic IPs starts at .100 so that you can create 98 static IP addresses, if necessary. Is that correct? If so, then I can probably start the block at .20 or something like that. I don't anticipate needing to create so many static IPs (or any, actually).
The lease time seems to be set for 10 days. That seems long to me. What would be a reasonable lease time, given that the wireless network is used both by true guests (visitors to our facility) as well as by staff (for their smart phones, iPads, etc.)?
Offhand, do you see any other parameters that should be changed in the config file?
Thanks so much for your help.
I assume that the block of dynamic IPs starts at .100 so that you can create 98 static IP addresses, if necessary. Is that correct? If so, then I can probably start the block at .20 or something like that. I don't anticipate needing to create so many static IPs (or any, actually).
The lease time seems to be set for 10 days. That seems long to me. What would be a reasonable lease time, given that the wireless network is used both by true guests (visitors to our facility) as well as by staff (for their smart phones, iPads, etc.)?
Offhand, do you see any other parameters that should be changed in the config file?
Thanks so much for your help.
ASKER
OK, I'm having trouble attaching the config file. Let me copy-and-paste it below.
# Sample udhcpd configuration file (/etc/udhcpd.conf)
# The start and end of the IP lease block
start 192.168.100.100 #default: 192.168.0.20
end 192.168.100.199 #default: 192.168.0.254
# The interface that udhcpd will use
interface eth0 #default: eth0
# The maximim number of leases (includes addressesd reserved
# by OFFER's, DECLINE's, and ARP conficts
max_leases 99 #default: 254
# If remaining is true (default), udhcpd will store the time
# remaining for each lease in the udhcpd leases file. This is
# for embedded systems that cannot keep time between reboots.
# If you set remaining to no, the absolute time that the lease
# expires at will be stored in the dhcpd.leases file.
#remaining yes #default: yes
# The time period at which udhcpd will write out a dhcpd.leases
# file. If this is 0, udhcpd will never automatically write a
# lease file. (specified in seconds)
#auto_time 7200 #default: 7200 (2 hours)
# The amount of time that an IP will be reserved (leased) for if a
# DHCP decline message is received (seconds).
#decline_time 3600 #default: 3600 (1 hour)
# The amount of time that an IP will be reserved (leased) for if an
# ARP conflct occurs. (seconds
#conflict_time 3600 #default: 3600 (1 hour)
# How long an offered address is reserved (leased) in seconds
#offer_time 60 #default: 60 (1 minute)
# If a lease to be given is below this value, the full lease time is
# instead used (seconds).
#min_lease 60 #defult: 60
# The location of the leases file
#lease_file /var/lib/misc/udhcpd.lease
# The location of the pid file
#pidfile /var/run/udhcpd.pid #default: /var/run/udhcpd.pid
# Everytime udhcpd writes a leases file, the below script will be called.
# Useful for writing the lease file to flash every few hours.
#notify_file #default: (no script)
#notify_file dumpleases # <--- useful for debugging
# The following are bootp specific options, setable by udhcpd.
#siaddr 192.168.0.22 #default: 0.0.0.0
#sname zorak #default: (none)
#boot_file /var/nfs_root #default: (none)
# The remainer of options are DHCP options and can be specifed with the
# keyword 'opt' or 'option'. If an option can take multiple items, such
# as the dns option, they can be listed on the same line, or multiple
# lines. The only option with a default is 'lease'.
#Examles
opt dns 172.16.200.254
option subnet 255.255.255.0
opt router 192.168.100.1
#opt wins 192.168.10.10
option dns 8.8.8.8 # appened to above DNS servers for a total of 3
option domain lollypop.org
option lease 864000 # 10 days of seconds
# Currently supported options, for more info, see options.c
#opt subnet
#opt timezone
#opt router
#opt timesrv
#opt namesrv
#opt dns
#opt logsrv
#opt cookiesrv
#opt lprsrv
#opt bootsize
#opt domain
#opt swapsrv
#opt rootpath
#opt ipttl
#opt mtu
#opt broadcast
#opt wins
#opt lease
#opt ntpsrv
#opt tftp
#opt bootfile
#opt wpad
# Static leases map
#static_lease 00:60:08:11:CE:4E 192.168.0.54
#static_lease 00:60:08:11:CE:3E 192.168.0.44
# Sample udhcpd configuration file (/etc/udhcpd.conf)
# The start and end of the IP lease block
start 192.168.100.100 #default: 192.168.0.20
end 192.168.100.199 #default: 192.168.0.254
# The interface that udhcpd will use
interface eth0 #default: eth0
# The maximim number of leases (includes addressesd reserved
# by OFFER's, DECLINE's, and ARP conficts
max_leases 99 #default: 254
# If remaining is true (default), udhcpd will store the time
# remaining for each lease in the udhcpd leases file. This is
# for embedded systems that cannot keep time between reboots.
# If you set remaining to no, the absolute time that the lease
# expires at will be stored in the dhcpd.leases file.
#remaining yes #default: yes
# The time period at which udhcpd will write out a dhcpd.leases
# file. If this is 0, udhcpd will never automatically write a
# lease file. (specified in seconds)
#auto_time 7200 #default: 7200 (2 hours)
# The amount of time that an IP will be reserved (leased) for if a
# DHCP decline message is received (seconds).
#decline_time 3600 #default: 3600 (1 hour)
# The amount of time that an IP will be reserved (leased) for if an
# ARP conflct occurs. (seconds
#conflict_time 3600 #default: 3600 (1 hour)
# How long an offered address is reserved (leased) in seconds
#offer_time 60 #default: 60 (1 minute)
# If a lease to be given is below this value, the full lease time is
# instead used (seconds).
#min_lease 60 #defult: 60
# The location of the leases file
#lease_file /var/lib/misc/udhcpd.lease
# The location of the pid file
#pidfile /var/run/udhcpd.pid #default: /var/run/udhcpd.pid
# Everytime udhcpd writes a leases file, the below script will be called.
# Useful for writing the lease file to flash every few hours.
#notify_file #default: (no script)
#notify_file dumpleases # <--- useful for debugging
# The following are bootp specific options, setable by udhcpd.
#siaddr 192.168.0.22 #default: 0.0.0.0
#sname zorak #default: (none)
#boot_file /var/nfs_root #default: (none)
# The remainer of options are DHCP options and can be specifed with the
# keyword 'opt' or 'option'. If an option can take multiple items, such
# as the dns option, they can be listed on the same line, or multiple
# lines. The only option with a default is 'lease'.
#Examles
opt dns 172.16.200.254
option subnet 255.255.255.0
opt router 192.168.100.1
#opt wins 192.168.10.10
option dns 8.8.8.8 # appened to above DNS servers for a total of 3
option domain lollypop.org
option lease 864000 # 10 days of seconds
# Currently supported options, for more info, see options.c
#opt subnet
#opt timezone
#opt router
#opt timesrv
#opt namesrv
#opt dns
#opt logsrv
#opt cookiesrv
#opt lprsrv
#opt bootsize
#opt domain
#opt swapsrv
#opt rootpath
#opt ipttl
#opt mtu
#opt broadcast
#opt wins
#opt lease
#opt ntpsrv
#opt tftp
#opt bootfile
#opt wpad
# Static leases map
#static_lease 00:60:08:11:CE:4E 192.168.0.54
#static_lease 00:60:08:11:CE:3E 192.168.0.44
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Remember to back up your original file first before making changes:
cp /etc/udhcpd.conf ~/
Also remember to start the dhcp service for the changes to take effect.
I do not use ubuntu, but I imagine this would work to restart it:
/etc/init.d/udhcpd restart
cp /etc/udhcpd.conf ~/
Also remember to start the dhcp service for the changes to take effect.
I do not use ubuntu, but I imagine this would work to restart it:
/etc/init.d/udhcpd restart
ASKER
Excellent. Everything worked as expected. Thanks so much, Savone. I think this solves a very vexing problem that I've had for several months now, ever since I installed the wireless network.
Glad I can help
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