SNI Routing with BIG-IP
In the previous article, The Three HTTP Routing Patterns, Lori MacVittie covers 3 methods of routing. Today we will look at Server Name Indication (SNI) routing as an additional method of routing HTTPS or any protocol that uses TLS and SNI. Using SNI we can route traffic to a destination without having to terminate the SSL connection. This enables several benefits including: Reduced number of Public IPs Simplified configuration More intelligent routing of TLS traffic Terminating SSL Connections When you have a SSL certificate and key you can perform the cryptographic actions required to encrypt traffic using TLS. This is what I refer to as “terminating the SSL connection” throughout this article. When you want to route traffic this is a chicken and an egg problem, because for TLS traffic you want to be able to route the traffic by being able to inspect the contents, but this normally requires being able to “terminate the SSL connection”. The goal of this article is to layer in traffic routing for TLS traffic without having to require having/knowing the original SSL certificate and key. Server Name Indication (SNI) SNI is a TLS extension that makes it possible to "share" certificates on a single IP address. This is possible due to a client using a TLS extension that requests a specific name before the server responds with a SSL certificate. Prior to SNI, the other options would be a wildcard certificate or Subject Alternative Name (SAN) that allows you to specify multiple names with a single certificate. SNI with Virtual Servers It has been possible to use SNI on F5 BIG-IP since TMOS 11.3.0. The following KB13452 outlines how it can be configured. In this scenario (from the KB article) the BIG-IP is terminating the SSL connection. Not all clients support SNI and you will always need to specify a “fallback” profile that will be used if a SNI name is not used or matched. The next example will look at how to use SNI without terminating the SSL connection. SNI Routing Occasionally you may have the need to have a hybrid configuration of terminating SSL connections on the BIG-IP and sending connections without terminating SSL. One method is to create two separate virtual servers, one for SSL connections that the BIG-IP will handle (using clientssl profile) and one that it will not handle SSL (just TCP). This works OK for a small number of backends, but does not scale well if you have many backends (run out of Public IP addresses). Using SNI Routing we can handle everything on a single virtual server / Public IP address. There are 3 methods for performing SNI Routing with BIG-IP iRule with binary scan a. Article by Colin Walker code attribute to Joel Moses b. Code Share by Stanislas Piron iRule with SSL::extensions Local Traffic Policy Option #1 is for folks that prefer complete control of the TLS protocol. It only requires the use of a TCP profile. Options #2 and #3 only require the use of a SSL persistence profile and TCP profile. SNI Routing with Local Traffic Policy We will skip option #1 and #2 in this article and look at using a Local Traffic Policy for SNI Routing. For a review of Local Traffic Policies check out the following DevCentral articles: LTM Policy Jan 2015 Simplifying Local Traffic Policies in BIG-IP 12.1 June 2016 In previous articles about Local Traffic Policies the focus was on routing HTTP traffic, but today we will use it to route SSL connections using SNI. In the following example, using a Local Traffic Policy named “sni_routing”, we are setting a condition on the SSL Extension “servername” and sending the traffic to a pool without terminating the SSL connection. The pool member could be another server or another BIG-IP device. The next example will forward the traffic to another virtual server that is configured with a clientssl profile. This uses VIP targeting to send traffic to another virtual server on the same device. In both examples it is important to note that the “condition”/“action” has been changed from occurring on “request” (that maps to a HTTP L7 request) to “ssl client hello”. By performing the action prior to any L7 functions occurring, we can forward the traffic without terminating the SSL connection. The previous example policy, “sni_routing”, can be attached to a Virtual Server that only has a TCP profile and SSL persistence profile. No HTTP or clientssl profile is required! This method can also be used to solve the issue of how to consolidate multiple SSL virtual servers behind a single virtual server that have different APM and/or ASM policies. This is similar to the architecture that is used by the Container Connector for Cloud Foundry; in creating a two-tier load balancing solution on a single device. Routed Correctly? TLS 1.3 has interesting proposals on how to obscure the servername (TLS in TLS?), but for now this is a useful and practical method of handling multiple SSL certs on a single IP. In the future this may still be possible as well with TLS 1.3. For example the use of a HTTP Fronting service could be a tier 1 virtual server (this is just my personal speculation, I have not tried, at the time of publishing this was still a draft proposal). In other news it has been demonstrated that a combination of using SNI and a different host header can be used for “domain fronting”. A method to enforce consistent policy (prevent domain fronting) would be to layer in additional conditions that match requested SNI servername (TLS extension) with requested HOST header (L7 HTTP header). This would help enforce that a tenant is using a certificate that is associated with their application and not “borrowing” the name and certificate that is being used by an adjacent service. We don’t think of a TLS extension as an attribute that can be used to route application traffic, but it is useful and possible on BIG-IP.Identity-centric F5 ADSP Integration Walkthrough
In this article we explore F5 ADSP from the Identity lense by using BIG-IP APM, BIG-IP SSLO and add BIG-IP AWAF to the service chain. The F5 ADSP addresses four core areas: Deployment at scale, Security against evolving threats, Deliver application reliably, Operate your day to day work efficiently. Each comes with its own challenges, but together they define the foundation for keeping systems fast, stable, and safe. Each architecture deployment example is designed to cover at least two of the four core areas: Deployment, Security, Delivery and XOps.F5 DNS/GTM External Monitor(EAV) with SNI support and response code check
I have used this monitor for XC Distributed Cloud as the HTTP LB share by default the same tenant IP address and SNI support is needed. You can order dedicated public IP addresses for each HTTP LB and enable "Default Load Balancer" ( https://my.f5.com/manage/s/article/K000152902 ) option but it will cost you extra 😉 The script is a modified version of External https health monitor for SNI-enabled pool as to handle response codes and to set the SNI globally for the entire pool and it's members. If you are uploading from Windows machine see External monitor fails to run as you could hit the bug. This could be needed for F5 DNS/GTM below 16.1 that do not support SNI in HTTPS monitors. The only mandatory variable is "SNI" that should be set in the external monitor config that references this uploaded bash script. The "URI" variable by default is set to "/" and "$2" variable by default is empty or 443, the default expected response code 200. #!/bin/sh # External monitoring script for checking HTTP status code # $1 = IP (::ffff:nnn.nnn.nnn.nnn notation or hostname) # $2 = port (optional; defaults to 443 if not provided) # Default SNI to IP if not explicitly provided node_ip=$(echo "$1" | sed 's/::ffff://') # Remove IPv6 compatibility prefix SNI=${SNI:-"$node_ip"} # Assign sanitized IP to SNI # Default variables MON_NAME=${MON_NAME:-"MyExtMon$$"} pidfile="/var/run/$MON_NAME.$1..$2.pid" # PID file path DEBUG=${DEBUG:-0} # Enable debugging if set to 1 EXPECTED_STATUS=${EXPECTED_STATUS:-200} # Default HTTP status code to 200 URI=${URI:-"/"} # Default URI DEFAULT_PORT=443 # Default port (used if $2 is unset) # Set port to default if $2 is not provided if [ -z "${2}" ]; then PORT=${DEFAULT_PORT} else PORT=${2} fi # Kill old process if pidfile exists if [ -f "$pidfile" ]; then kill -9 -$(cat "$pidfile") > /dev/null 2>&1 fi echo "$$" > "$pidfile" # Perform the HTTP(S) request via single curl (fetch status code only) status_code=$(curl -s -o /dev/null -w '%{http_code}' --connect-timeout 5 --resolve "${SNI}:${PORT}:${node_ip}" "https://${SNI}:${PORT}${URI}") # Cleanup rm -f "$pidfile" > /dev/null 2>&1 # Output server status based on HTTP status code match if [ "$status_code" -eq "$EXPECTED_STATUS" ]; then echo "up" else echo "down" fi # Debugging if [ "$DEBUG" -eq 1 ]; then echo "Debugging on..." echo "SNI=${SNI}" echo "URI=${URI}" echo "IP=${node_ip}" echo "PORT=${PORT}" echo "MON_NAME=${MON_NAME}" echo "STATUS_CODE=${status_code}" echo "EXPECTED_STATUS=${EXPECTED_STATUS}" echo "curl -s -o /dev/null -w '%{http_code}' --connect-timeout 5 --resolve ${SNI}:${PORT}:${node_ip} https://${SNI}:${PORT}${URI}" fi
Is it possible to select ASM BoT profile from irule?
Hi. . Is it possible to select BoT profile from irule? . Concept is we have different set of IP which need to allow "some" BoT type. That why we can't use whitelist IP in BoT profile because it will allow all BoT type. So We want to use iRule to check if it IP A > use BoT profile which have some exception, but if all other IP > use normally BoT profile. . when HTTP_REQUEST { # Check IP and select BoT profile from that if { [IP::client_addr] eq "A" } { ASM::enable allow_some_bot_profile } else { ASM::enable normally_bot_profile } } ps. I didn't see any document about how to select BoT profile. So I'm not sure if ASM::enable can do that.BIG-IP Next for Kubernetes Nvidia DPU deployment walkthrough
Introduction Modern AI factories—hyperscale environments powering everything from generative AI to autonomous systems—are pushing the limits of traditional infrastructure. As these facilities process exabytes of data and demand near-real-time communication between thousands of GPUs, legacy CPUs struggle to balance application logic with infrastructure tasks like networking, encryption, and storage management. Data Processing Units (DPUs), purpose-built accelerators that offload these housekeeping tasks, freeing CPUs and GPUs to focus on what they do best. DPUs are specialized system-on-chip (SoC) devices designed to handle data-centric operations such as network virtualization, storage processing, and security enforcement. By decoupling infrastructure management from computational workloads, DPUs reduce latency, lower operational costs, and enable AI factories to scale horizontally. BIG-IP Next for Kubernetes and Nvidia DPU Looking at F5 ability to deliver and secure every app, we needed it to be deployed at multiple levels, a crucial one being edge and DPU. Installing F5 BIG-IP Next for Kubernetes on Nvidia DPU requires installing Nvidia’s DOCA framework to be installed. What’s DOCA? NVIDIA DOCA is a software development kit for NVIDIA BlueField DPUs. BlueField provides data center infrastructure-on-a-chip, optimized for high-performance enterprise and cloud computing. DOCA is the key to unlocking the potential of the NVIDIA BlueField data processing unit (DPU) to offload, accelerate, and isolate data center workloads. With DOCA, developers can program the data center infrastructure of tomorrow by creating software-defined, cloud-native, GPU-accelerated services with zero-trust protection. Now, let's explore BIG-IP Next for Kubernetes components, The BIG-IP Next for Kubernetes solution has two main parts: the Data Plane - Traffic Management Micro-kernel (TMM) and the Control Plane. The Control Plane watches over the Kubernetes cluster and updates the TMM’s configurations. The BIG-IP Next for Kubernetes Data Plane (TMM) manages the supply of network traffic both entering and leaving the Kubernetes cluster. It also proxies the traffic to applications running in the Kubernetes cluster. The Data Plane (TMM) runs on the BlueField-3 Data Processing Unit (DPU) node. It uses all the DPU resources to handle the traffic and frees up the Host (CPU) for applications. The Control Plane can work on the CPU or other nodes in the Kubernetes cluster. This makes sure that the DPU is still used for processing traffic. Use-case examples: There are some recently awesome use cases released by F5’s team based on conversation and work from the field. Let’s explore those items: Protecting MCP servers with F5 BIG-IP Next for Kubernetes deployed on NVIDIA BlueField-3 DPUs LLM routing with dynamic load balancing with F5 BIG-IP Next for Kubernetes deployed on NVIDIA BlueField-3 DPUs F5 optimizes GPUs for distributed AI inferencing with NVIDIA Dynamo and KV cache integration. Deployment walk-through In our demo, we go through the configurations from BIG-IP Next for Kubernetes Main BIG-IP Next for Kubernetes features L4 ingress flow HTTP/HTTPs ingress flow Egress flow BGP integration Logging and troubleshooting (Qkview, iHealth) You can find a quick walk-through via BIG-IP Next for Kubernetes - walk-through Related Content BIG-IP Next for Kubernetes - walk-through BIG-IP Next for Kubernetes BIG-IP Next for Kubernetes and Nvidia DPU-3 walkthrough BIG-IP Next for Kubernetes F5 BIG-IP Next for Kubernetes deployed on NVIDIA BlueField-3 DPUs
f5 client certificate forwarding
i have website secure over F5 , it require client certificate which i need to forward it to the server. i don't f5 to validate the certifcate . just i need to pass it to sever.. i have add in ssl profile the client certificate as " require" , and i have add the root CA as Advertised Certificate Authorities because the client will use self sighn certificate .. in irule i did the below: CLIENTSSL_CLIENTCERT { if { [SSL::cert count] > 0 } { set client_cert [X509::whole [SSL::cert 0]] set session_cert $client_cert } } when HTTP_REQUEST { if {[info exists session_cert]} { HTTP::header replace "X-Client-Cert" $session_cert } now when i try to access the portal, certifcate popup is displayed and after choose the certifcate i got " the site can't provide a secure connection, err_ssl_protocol_error .. and in f5 i see the client certifcicate is attach to the header. so what might be the issue?F5 Scalable App Delivery & Security for Hybrid Environments
As enterprises modernize and expand their digital services, they increasingly deploy multiple instances of the same applications across diverse infrastructure environments—such as VMware, OpenShift, and Nutanix—to support distributed teams, regional data sovereignty, redundancy, or environment-specific compliance needs. These application instances often integrate into service chains that span across clouds and data centers, introducing both scale and operational complexity. F5 Distributed Cloud provides a unified solution for secure, consistent application delivery and security across hybrid and multi-cloud environments. It enables organizations to add workloads seamlessly—whether for scaling, redundancy, or localization—without sacrificing visibility, security, or performance.Modern Deployment and Security Strategies for Kubernetes with NGINX Gateway Fabric
Kubernetes has become the foundation for cloud-native applications. However, managing and routing traffic within clusters remains a challenging issue. The traditional Ingress resource, though helpful in exposing services, has shown limitations. Its loosely defined specifications often cause controller-specific behaviors, complicated annotations, and hinder portability across different environments. These challenges become even more apparent as organizations scale their microservices architectures. Ingress was designed primarily for basic service exposure and routing. While it can be extended with annotations or custom controllers, it lacks first-class support for advanced deployment patterns such as canary or blue-green releases. This forces teams to rely on add-ons or vendor-specific features, which adds complexity and reduces portability.BIG-IP BGP Routing Protocol Configuration And Use Cases
Is the F5 BIG-IP a router? Yes! No! Wait what? Can the BIG-IP run a routing protocol? Yes. But should it be deployed as a core router? An edge router? Stay tuned. We'll explore these questions and more through a series of common use cases using BGP on the BIG-IP... And oddly I just realized how close in typing BGP and BIG-IP are, so hopefully my editors will keep me honest. (squirrel!) In part one we will explore the routing components on the BIG-IP and some basic configuration details to help you understand what the appliance is capable of. Please pay special attention to some of the gotchas along the way. Can I Haz BGP? Ok. So your BIG-IP comes with ZebOS in order to provide routing functionality, but what happens when you turn it on? What do you need to do to get routing updates in to the BGP process? And well does my licensing cover it? Starting with the last question… tmsh show /sys license | grep "Routing Bundle" The above command will help you determine if you’re going to be able to proceed, or be stymied at the bridge like the Black Knight in the Holy Grail. Fear not! There are many licensing options that already come with the routing bundle. Enabling Routing First and foremost, the routing protocol configuration is tied to the route-domain. What’s a route-domain? I’m so glad you asked! Route-domains are separate Layer 3 route tables within the BIG-IP. There is a concept of parent and child route domains, so while they’re similar to another routing concept you may be familiar with; VRF’s, they’re no t quite the same but in many ways they are. Just think of them this way for now. For this context we will just say they are. Therefore, you can enable routing protocols on the individual route-domains. Each route-domain can have it’s own set of routing protocols. Or run no routing protocols at all. By default the BIG-IP starts with just route-domain 0. And well because most router guys live on the cli, we’ll walk through the configuration examples that way on the BIG-IP. tmsh modify net route-domain 0 routing-protocol add { BGP } So great! Now we’re off and running BGP. So the world know’s we’re here right? Nope. Considering what you want to advertise. The most common advertisements sourced from the BIG-IP are the IP addresses for virtual servers. Now why would I want to do that? I can just put the BIG-IP on a large subnet and it will respond to ARP requests and send gratuitous ARPs (GARP). So that I can reach the virtual servers just fine. <rant> Author's opinion here: I consider this one of the worst BIG-IP implementation methods. Why? Well for starters, what if you want to expand the number of virtual servers on the BIG-IP? Well then you need to re-IP the network interfaces of all the devices (routers, firewalls, servers) in order to expand the subnet mask. Yuck! Don't even talk to me about secondary subnets. Second: ARP floods! Too many times I see issues where the BIG-IP has to send a flood of GARPs; and well the infrastructure, in an attempt to protect its control plane, filters/rate limits the number of incoming requests it will accept. So engineers are left to try and troubleshoot the case of the missing GARPs Third: Sometimes you need to migrate applications to maybe another BIG-IP appliance as it grew to big for the existing infrastructure. Having it tied to this interface just leads to confusion. I'm sure there's some corner cases where this is the best route. But I would say it's probably in the minority. </rant> I can hear you all now… “So what do you propose kind sir?” See? I can hear you... Treat the virtual servers as loopback interfaces. Then they’re not tied to a specific interface. To move them you just need to start advertising the /32 from another spot (Yes. You could statically route it too. I hear you out there wanting to show your routing chops.) But also, the only GARPs are those from the self-ip's This allows you to statically route of course the entire /24 to the BIG-IP’s self IP address, but also you can use one of them fancy routing protocols to announce the routes either individually or through a summarization. Announcing Routes Hear ye hear ye! I want the world to know about my virtual servers. *ahem* So quick little tangent on BIG-IP nomenclature. The virtual server does not get announced in the routing protocol. “Well then what does?” Eery mind reading isn't it? Remember from BIG-IP 101, a virtual server is an IP address and port combination and well, routing protocols don’t do well with carrying the port across our network. So what BIG-IP object is solely an IP address construct? The virtual-address! “Wait what?” Yeah… It’s a menu item I often forget is there too. But here’s where you let the BIG-IP know you want to advertise the virtual-address associated with the virtual server. But… but… but… you can have multiple virtual servers tied to a single IP address (http/https/etc.) and that’s where the choices for when to advertise come in. tmsh modify ltm virtual-address 10.99.99.100 route-advertisement all There are four states a virtual address can be in: Unknown, Enabled, Disabled and Offline. When the virtual address is in Unknown or Enabled state, its route will be added to the kernel routing table. When the virtual address is in Disabled or Offline state, its route will be removed if present and will not be added if not already present. But the best part is, you can use this to only advertise the route when the virtual server and it’s associated pool members are all up and functioning. In simple terms we call this route health injection. Based on the health of the application we will conditionally announce the route in to the routing protocol. At this point, if you’d followed me this far you’re probably asking what controls those conditions. I’ll let the K article expand on the options a bit. https://my.f5.com/manage/s/article/K15923612 “So what does BGP have to do with popcorn?” Popcorn? Ohhhhhhhhhhh….. kernel! I see what you did there! I’m talking about the operating system kernel silly. So when a virtual-address is in an unknown or enabled state and it is healthy, the route gets put in the kernel routing table. But that doesn’t get it in to the BGP process. Here is how the kernel (are we getting hungry?) routes are represented in the routing table with a 'K' This is where the fun begins! You guessed it! Route redistribution? Route redistribution! And well to take a step back I guess we need to get you to the ZebOS interface. To enter the router configuration cli from the bash command line, simply type imish. In a multi-route-domain configuration you would need to supply the route-domain number but in this case since we’re just using the 0 default we’re good. It’s a very similar interface to many vendor’s router and switch configuration so many of you CCIE’s should feel right at home. It even still lets you do a write memory or wr mem without having to create an alias. Clearly dating myself here.. I’m not going to get in to the full BGP configuration at this point but the simplest way to get the kernel routes in to the BGP process is simply going under the BGP process and redisitrubting the kernel routes. BUT WAIT! Thar be dragons in that configuration! First landmine and a note about kernel routes. If you manually configure a static route on the BIG-IP via tmsh or the tmui those will show up also as kernel routes Why is that concerning? Well an example is where engineers configure a static default route on the BIG-IP via tmsh. And well, when you redistribute kernel routes and that default route is now being advertised into BGP. Congrats! AND the BIG-IP is NOT your default gateway hilarity ensues. And by hilarity I mean the type of laugh that comes out as you're updating your resume. The lesson here is ALWAYS when doing route redistribution always use a route filter to ensure only your intended routes or IP range make it in to the routing protocol. This goes for your neighbor statements too. In both directions! You should control what routes come in and leave the device. Another way to have some disasterous consequences with BIG-IP routing is through summarization. If you are doing summarization, keep in mind that BGP advertises based on reachability to the networks it wants to advertise. In this case, BGP is receiving it in the form of kernel routes from tmm. But those are /32 addresses and lots of them! And you want to advertise a /23 summary route. But the lone virtual-address that is configured for route advertisement; and the only one your BGP process knows about within that range has a monitor that fails. The summary route will be withdrawn leaving all the /23 stranded. Be sure to configure all your virtual-addresses within that range for advertisement. Next: BGP Behavior In High Availability Configurations
