F5 GTM Topology - load balance one wideip with 2 datacenters
Hi DC members, I have some confusions in deploying the GTM toplogy. As from my understanding, there are 2 methods to LB using the topology : 1. WideIP Level 2. Pool Level Here is the setup : DC 1 : 2 x LTM (HA) , 1 x GTM DC 2 : 2 x LTM (HA) , 1 x GTM 2 sets of users : Country A, Country B. The requirements : Both users (CountryA & CountryB) will be using the same WideIP (ie: Scenario: User from Country A will have to connect apps in DC1 , and in the event of server failure in DC1, it will be routed to DC2, User from Country B will have to connect apps in DC2 , and in the event of server failure in DC2, it will be routed to DC1, vice versa. Below is my configurations : Wide IP : www.abc.com , PoolA : VS1 in DC1, VS2 in DC2, LB Method : Topology Topology records: Subnet A , Destination DC1, Weight = 200 | Subnet A , Destination DC2, Weight = 100 | Subnet B , Destination DC2, Weight = 200 | Subnet B , Destination DC1, Weight = 100 Does this configurations correct? Thanks in advance!
GTM and Topology
Hi, I am quite new to DNS/GTM stuff so I had no chance yet to dig into how Topology LB works and what can be done. Wonder if such configuration is possible: Setup: Two DC - DC1 and DR1 LDNS in each DC sending request to GTM (LDNS_DC1, LDNS_DR1) Servers in each DC - defined as Generic Host GTM serwing one Wide IP pointing to Servers in both DC I would like to achieve this result: When LDNS_DC1 sends request logic is: If there is any Srv active in DC1 return IP of any (based on RR) If there is no active Srv in DC1 return IP of any active Srv in DR1 (based on RR) When LDNS_DR1 sends request logic is: If there is any Srv active in DR1 return IP of any (based on RR) If there is no active Srv in DR1 return IP of any active Srv in DC1 (based on RR) So depending on which LDNS issued request logic is switched around. Is that possible without iRule using just LB available at Wide IP and Pool level? Side question: Which LB methods will work at all for Generic Host? I guess in this case all is based on analyzing communication between LDNS and GTM (no data that is provided when BIG-IP type of server is used)
GTM Wide IP Topology Based Load Balancing
Hello, I'm interested in creating an active / active GTM record that load balances at the wide IP level based on typologies. We already have a small implementation in place where I work that was setup before my time, but I've been getting inconsistent results. Basically I have a wide IP created with two pools and only one server in each pool. There is a topology record created as follows:  My source IP is 10.67.36.12 so based on the topology record defined above I should always get directed to Virtual-CGS Topology, but when I test it out I'll sometimes go to Virtual-CGS and sometimes Virtual-PD. From reading documentation it reads like this type of topology setup is more for load balancing at the pool level and not wide IP level? Is that the case? Cheers, Brian
GTM Topology - LDNS Request
Hello! I have some doubts how the GTM works in its Topology LB records. If I have the following: WIP Pool www.mydomain.com Pool A <- Prefered: Topology, Alternate: Round Robin, Fallback:Return to DNS www.otherdomain.com Pool B <- Prefered: Topology, Alternate: Round Robin, Fallback:Return to DNS www.onedomain.com Pool C <- Prefered: Topology, Alternate: Round Robin, Fallback:Return to DNS www.lastdomain.com Pool D <- Prefered: Topology, Alternate: Round Robin, Fallback:Return to DNS Order LDNS Request Source Destination Weight 1 10.20.0.0/16 Pool A 1 2 10.30.0.0/16 Pool B 1 3 10.40.0.0/16 Pool A 1 4 10.0.0.0/16 Pool D 1 My Scenario Question are: 1- If a query is made for "www.mydomain.com" from source IP 10.20.0.1, Is Pool A served? 2- If a query is made for "www.mydomain.com" from source IP 192.168.10.1, Will Round Robin be served? 3- If a query is made for "www.lastdomain.com" from source IP 10.20.0.1, Is Pool D served? Will Topology logic not catch the first line 10.20.0.0/16 > Pool A? Thank you JohnR
GTM Topology Load Balancing - Order of Operation
Two-part question: 1.) For wide IP-level topology load balancing, what takes precedence: order, weight, or prefix length? (Assuming topology load balancing is choosing between pools based on source IP subnet). 2.) This question came about due to a situation in which I'm seeing some unexpected LB results. Given the below topology configuration (11.x) 1 IP Subnet is 10.0.1.0/29 Pool is West_DC_Pool 1 2 IP Subnet is 10.0.1.0/24 Pool is West_DC_Pool 150 3 IP Subnet is 10.0.0.0/24 Pool is East_DC_Pool 1 4 IP Subnet is 10.0.0.0/16 Pool is East_DC_Pool 100 The LDNS server IP is 10.0.1.5 (there's only one LDNS server at the moment) The East_DC_Pool is being chosen every time. Based on the logs, it seems to be comparing 1 (10.0.1.0/29 with a weight of 1) to 4 (10.0.0.0/16 with a weight of 100) and therefore 4 is winning based on a weight of 100. No mention of 2 (10.0.1.0/24 with a weight of 150) in the logs. If I delete 1, then 2 (10.0.1.0/24 with weight of 150) wins so traffic is then sent to West_DC_Pool. Now re-adding 1 (10.0.0.0/29 with weight 1) causes 4 (East_DC_Pool) to win again. Is this expected behavior??? I would have expected in all cases (with a LDNS IP of 10.0.1.5) that traffic would be routed to the West_DC_Pool based on either longest prefix match(1 would win), weight(2 would win), or order (again 1 would win). But maybe there's something about the order of operation that I'm unaware of. Thanks in advance, DaveQuestion on GTM load balancing
Dear All, I'm looking for an approach for my client requirements which I have explained below : Currently, one DNS(wide-ip) is configured on GTM with topology as the load balancing mechanism so that requests from EMEA/US regions are processed by VS1 on LTM1 and APAC by VS2 on LTM2. Needless to say, VS1 and VS2 are configured with their respective location backend servers in pools. However, my clients request is that all requests from US should be processed by VS2 configured on LTM2 instead of current setup wherein they are processed by VS1 on LTM1 as explained above. Can anyone suggest me if its possible to configure such load balancing on GTM or can it be done on LTM level(iRule) keeping transparent on GTM level. Please advice. Br, MSK
GTM - Data Center destinations in Topology Records and Topology Load Balancing at the Wide IP level
I am hearing that when doing Topology based Load Balancing at the Wide IP level, your topology records using Data Centers as the Destination will be ignored. In fact, this is what I'm seeing with my own eyes. Why would this be the only Destination type that does not work with Topology LB'ing at the Wide IP level? It would be so very useful. Am I missing something?BIG-IP DNS Topology LB selection - topology score vs QoS score
Im trying to figure out when/why topology score vs qos score is being used for the DNS LB. When we use topo LB in WIP to select a certain pool I get the following: SIN-F5I01 from {my internal src IP} [test.glb.lab.int A] [topology selected pool (AMS-Exchange-GTM_Pool) - topology score (10) is higher] [topology skipped pool (FRA-Exchange-GTM_Pool) - topology score (0) is not higher] [topology selected pool (AMS-Exchange-GTM_Pool) with the highest topology score (10)] When I do the same on a pool to select a certain pool member: SIN-F5I01 from {my internal src IP} [time.glb.lab.int A] [pool member check succeeded (chi-ntp01.labint) [QoS selected pool member (chi-ntp01.lab.int) - QoS score (0) is higher] [pool member check succeeded (sin-ntp01.lab.int) [QoS selected pool member (sin-ntp01.lab.int) - QoS score (429496729600) is higher] [pool member check succeeded (ams-ntp01.lab.int) - [QoS skipped pool member (ams-ntp01.lab.int) - QoS score is not higher] [QoS selected pool member (sin-ntp01.lab.int)] In both cases we are using Topo LB and dont assign any gtm-score to any VIP. Question: Is this just the default behavior - pool member selection vs pool selection? On the QoS score, how exactly is this calculated? I figured changing the weight in the topo record changes the score (weight 1 = QoS score (42949672900), weight 10 = QoS score (429496729600)) Many thanks in advanceF5 GTM Topology LB with mutiple wideIP, different conditions (pool selection)
Hi, I have a new requirement for my client. Previously, we have setup for their exchange server and is working perfectly in topology LB. Existing scenario (simple expalanation) Datacenter A Source IP X : 10.10.x.x , Pool A : DCA_VS Datacenter B Source IP Y : 20.20.x.x , Pool B : DCB_VS Topology Design : Source IP X, Pool is Pool A, Score 200 Source IP X, Pool is Pool B, Weight 100 Source IP Y, Pool is Pool B, Weight 200 Source IP Y, Pool is Pool A, Weight 100 On the wideIP configurations (WideIP : exchange.abc.com), i have selected "Topology" as the load balance method. Here comes the new requirement: Datacenter A Source IP X : 10.10.x.x , Pool C : DCC_VS Datacenter B Source IP Y : 20.20.x.x , Pool D : DCD_VS How do i apply these new topology requirements with new WideIP? Example: sharepoint.abc.com. Because in the WideIP loadbalancing options, we cannot select which topology conditions the wideIP should look for. NOTES : Source IP X will always prefer Datacenter A (resources) , while Source IP Y will always prefer Datacenter B (resources) as their primary. Thanks in advance!!!Topology Records and WideIP vs. Pool Based Topology Decisions
Hello all, I've never really been able to get a definitive answer on this. From the documentation about configuring topology based DNS on the GTM it shows examples of configuring topology at the wide IP level by creating topology records that reference the pool. And when configuring topology at the pool level the documentation shows examples of creating topology records that reference the data center. In production we have topology DNS configured at the wide IP level (with two pools and one virtual server in each pool) and our topology records reference data centers. It'll work if at the pool level you have the topology set first and none as your second and third options. But if you were to change the second or third option to something else you will get mixed results and won't follow the toplogy records. Can anyone explain this? Thanks, Brian