Forum Discussion
NimbostratusGTM with or without LTM?
Hi there, I need to know, if we have web servers to publish on web in backup and main data centers, is it a must to have GTM and LTM toghether in every DC, or for example in backup site(which has the same web services published)is it possible to have just the GTM without LTM and the GTM directly doing the health monitor of these services? thanks Shahrzad
10 Replies
nitass_89166Noctilucent
you can think gtm is dns server (but intelligence). one gtm is fine but multiple provide load sharing and redundancy.
ltm is server load balancer. user traffic does not go through gtm.
hope this helps.
Shahrzad_84598Dear nitass, thanks for your reply.It helped a lot. You wrote "one gtm is fine but multiple provide load sharing and redundancy", by "one gtm" do you mean in one DC one GTM is enough, or for the whole scenario, I mean is it possible to have just one gtm for two or more DCs?Or it is a must to have one GTM and one LTM for each Data Center?
- nitass
Employee
you can think gtm is dns server (but intelligence). one gtm is fine but multiple provide load sharing and redundancy.
ltm is server load balancer. user traffic does not go through gtm.
hope this helps.
- Shahrzad_84598Dear nitass, thanks for your reply.It helped a lot. You wrote "one gtm is fine but multiple provide load sharing and redundancy", by "one gtm" do you mean in one DC one GTM is enough, or for the whole scenario, I mean is it possible to have just one gtm for two or more DCs?Or it is a must to have one GTM and one LTM for each Data Center?
- nitass_89166
I mean is it possible to have just one gtm for two or more DCs?
yes but if that dc is down, your domain will be gone.
- Shahrzad_84598we don`t have the GTM yet, but I read in some other questions on DEV that we need to add for example LTM virtual server objects to GTM so it can iquery about the health of those services from LTM, if it is true then without LTM how can we setup the GTM? Also does GTM integrates with other brands, like cisco ACE?
- nitass
I mean is it possible to have just one gtm for two or more DCs?
yes but if that dc is down, your domain will be gone.
- Shahrzad_84598we don`t have the GTM yet, but I read in some other questions on DEV that we need to add for example LTM virtual server objects to GTM so it can iquery about the health of those services from LTM, if it is true then without LTM how can we setup the GTM? Also does GTM integrates with other brands, like cisco ACE?
- nitass
if it is true then without LTM how can we setup the GTM? Also does GTM integrates with other brands, like cisco ACE?
yes, gtm can monitor service on server or on other server load balancer vendor too. if there is ltm in dc, it is preferred to let gtm talk to ltm rather than talking to server directly.
StephanMantheyNacreous
If you plan to integrate GTM, I recommend not to use it on the same device combined with your LTMs.
From the implementation / operation perspective a dedicated GTM appliance is much easier to handle.
As DNS has it´s build-in redundancy (multiple NS records) it´s not necessary to implement GTMs as redundant pairs (device-groups) per site.
