Sticky IP is one that does not change EVERY time that a connection is made but is not guaranteed to be the same indefinitely. I had a sticky IP with Pipex and had the same IP address for about 18 months. It only changed when I moved (house not ISP) and now have a dynamic address.
The address is most likely to change if you disconnect for quite a long time (vague but depends upon ISP, the size of their address pool, number of customers etc).
Well, there is. Static IP address persist over time. Stick IP address persist as ling as the ISP chooses to let them. My IP address will change if I switch my cable modem connection from my router to my primary machine, even though both pieces of hardware have the same MAC address. It may also change if my ISP modifies the signal distribution configuration.
Unless you have need to contact your machine from outside your local network. Some of us travel and have need to contact the home base on occasion.
One way to resolve the issue, if you have need to, is to sign up for one of the free domain name mapping services (e.g. dyndns.org) and install a client that keeps your name to IP address association up to date.
I use dyndns.org and have an ADSL router. The canonical name for my machine points to the new IP adress when the IP changes on my router ( every time router is restarted). I am using dnsupdate on my Mac to do this:
So, not a mail message but you can always access your machine which I assume is what you want.
There's one other important distinction if you are trying to run a server on a "sticky" IP, especially a mail server. The reverse lookup will probably indicate that the IP is dynamic, and so will be listed in a number of widely-used block lists. Not a problem if you route outbound email through your ISP, but a potential liability if you're trying to run a mail server on the cheap!
I view the main distinction to be WHERE the address is configured. As a static address, it would be configured on the workstation. As a sticky address, the client would use dhcp and the server would assign that same address everytime based on dhcp configuration. I have some microsoft RAS users that require a static ip for a particular application. Instead of having the user configure their RAS entry with the static address, I just configure the user to get the same address. I'm sure you could accomplish the same thing by mac address as well.
Quite right. The static IP persists over time, until your ISP changes it.
Right, but not different from static IPs. The different Tom sees between static and sticky exists only in his imagination.
But that's a dynamic IP. It is neither static nor sticky.
There are quite a few users on SBC dsl service, who have the SBC static package (usually described as sticky IPs), who have correct reverse DNS identifying their hostnames in a way that does not suggest dynamic. Hmm, they even have whois records on ARIN for their block of sticky IPs. The whois record does indicate that these are part of a larger SBC block.
Sticky IPs are a term coined by non-Ameritech regions of SBC for a block of static IPs routed through a single connecting PPPoE IP (Ameritech has always done static adsl IPs that way). For example the PPPoE connection is configured like dynamic, but based on the login, the same block of static IPs are routed from the internet to that PPPoE IP.
Not sure how those people would refer to our sdsl connection at work where WAN IP and default gateway of modem/router is unrelated to our /29 public static IPs behind it. Our ISP may use that WAN IP as a gateway to our subnet, but that is as transparent as normal internet routing to reach our public static IPs.
Sticky IP, is basically a database within a device that ensures returning traffic is routed back to the sending device when load-balancing is in use.
If 3 firewalls are used and traffic load balanced between them It is important that connection based trafic such as TCP uses the same firewall in both directions for a particular connection for it to function correctly. To achieve this a sticky IP database is set up in the device's either side of the F/W's noting the source IP address of the packet along with the IP address of the Firewall it was recieved from. Return traffic where the destination IP address already exists in the database as a source address will be delivered to the relevent firewall and not in a load balance round robin fashion. IP destinations not in the database will just use the round robin method to load balance.
This of course could be taken to higher layers than just layer 3 but would possibly defeat the object as we want as little CPU time wasted on the single device feeding the 3 firewalls, as it is the CPU usage on the firewall that made us want to load share in the first instance.
I think he's seeing an artifact of the way DHCP works. When a DHCP client requests an IP, it includes the IP it would like to have, which is typically the last IP it had. If the IP is available, the server will assign that IP to the client.
If the client doesn't specify a particular IP in its request, the server may remember the IP that it gave out to that MAC address last time, and give it out again if it's available.
So what's probably happening when he switches from his router to his primary machine, is that the machine is proposing a different IP than the router had.
I have read here that most peoples interpretation of Sticky IP is a DHCP allocated address that does not change, i.e. end user devices will accept an IP address from the ISP but the ISP itself is using a static allocation, or a generally static connection that can change dynamically under certain conditions????
I have not seen this in use at configuration level (on Cisco routers), Does it actually exist or is it just a conceptual name for this behaviour? (my previous post shown below does however use Sticky IP in configuration on a CSM module in a Cisco L3 switch)
I personally can not see the advantage of a service provider reserving an IP address for a customer and then allocating it dynamically (apart from ease of set up for the customers equipment) as surely this defeats the purpose of DHCP in preserving IPv4 address space on the assumption that not all users will be logged on so the ISP needs a smaller pool of addresses than the size of it's consumer base.
I am also dubious about the use of sticky where a customer has used DNS to locate their IP address that has been stickily applied as the administration involved every time it changed would be stupid. Why not just have a static IP.
My last point is based on something I had not actually thought of before this post. What impact is the use of always on Broadband having on the IPv4 address space? Previously home users had dial up DHCP allocated and due to charging/time restraints were not on 24/7 so did not use an IP address when offline. Broadbasnd in it's basic sence is simular in that if a DSL modem is used the IP address is allocated when the PC is on only. But with many people using DSL/Routers that are never turned off then surely the IPv4 address space is taking a battering, If everyone used a router then we may as well all have a static IP address.
Paste-------------- My previous comments regarding sticky IP
In practice, for the DSL world, it is usually IP addresses assigned during PPPoE negotiation, where the assigned IP does not change.
That's only one of the purposes of DHCP.
A computer needs to know its IP address, gateway router address, DNS server address, and perhaps other information. If you configure the IP address directly in customer equipment, then you have to also configure the other information. An ISP has more flexibility if that information can be assigned dynamically. It allows network reconfiguration without having to require customers to change their settings.
For what is usually called sticky IP, at least in the DSL world, you will always get the same IP. Therefore there are no serious problems in setting up DNS and reverse DNS for your hosts.
That's unrelated to the static/sticky question.
I'm sure it increases pressure on the IPv4 space. But perhaps it doesn't increase it all that much. At least for home users, many will want to be connected for much of the evening. You need enough IP addresses to handle the maximum load.
If everybody turned off their equipment when they were not using it, you would have lots of free IP addresses at 3 a.m., but you wouldn't free up very many at 8 p.m. It's the peak load that counts for the number of IPs needed.
Not really. The ISP still benefits from dynamic address assignment. That way it can move a block of IPs from one region to another, depending on where the load is. If everyone had static or sticky addresses, you would have to give your users advanced notification of IP address change before you could move blocks. And you would have to deal with irate customers who don't want to change.
Speaking from not knowing any actual stats on this, I believe the pressure on the IPv4 space is not what it once was thought to be. The rfc's for private address space and NAT has freed up a lot of addresses. Now, companies with thousands of employees can accomplish their internal networking with private addressing. Even ISP's are using private addresses for their equipment that serves the internet. I'm sure the creation of broadband is now moving the trend back into the direction of using up more addresses, but I believe the situation is not critical at this point. There are still public blocks available if you can prove the need.
If you have a static IP or block it is assigned to YOU by whoever is your upstream. It is a contracted thing or should be. And it should not change without consent or business interruptions such as the upstream going out of business.
Dynamic means the IP can change at any time.
I and others I know use sticky to refer to dynamic IPs that seem to stay the same for months on end. Here in central NC, TWC gives you an IP and you usually keep it for months. Then it might change to another in your subnet or I've even seen them reassign the area to a different /8.
At the other end Bellsouth changes IP addresses everytime you authenticate via PPPoE. Or they used to, I don't use them much anymore.