Getting Started with Citrix ADC
Deploy a Citrix ADC VPX instance
Optimize Citrix ADC VPX performance on VMware ESX, Linux KVM, and Citrix Hypervisors
Apply Citrix ADC VPX configurations at the first boot of the Citrix ADC appliance in cloud
Install a Citrix ADC VPX instance on Microsoft Hyper-V servers
Install a Citrix ADC VPX instance on Linux-KVM platform
Prerequisites for Installing Citrix ADC VPX Virtual Appliances on Linux-KVM Platform
Provisioning the Citrix ADC Virtual Appliance by using OpenStack
Provisioning the Citrix ADC Virtual Appliance by using the Virtual Machine Manager
Configuring Citrix ADC Virtual Appliances to Use SR-IOV Network Interface
Configuring Citrix ADC Virtual Appliances to use PCI Passthrough Network Interface
Provisioning the Citrix ADC Virtual Appliance by using the virsh Program
Provisioning the Citrix ADC Virtual Appliance with SR-IOV, on OpenStack
Configuring a Citrix ADC VPX Instance on KVM to Use OVS DPDK-Based Host Interfaces
Deploy a Citrix ADC VPX instance on Microsoft Azure
Network architecture for Citrix ADC VPX instances on Microsoft Azure
Configure multiple IP addresses for a Citrix ADC VPX standalone instance
Configure a high-availability setup with multiple IP addresses and NICs
Configure a high-availability setup with multiple IP addresses and NICs by using PowerShell commands
Configure a Citrix ADC VPX instance to use Azure accelerated networking
Configure HA-INC nodes by using the Citrix high availability template with Azure ILB
Configure a high-availability setup with Azure external and internal load balancers simultaneously
Configure address pools (IIP) for a Citrix Gateway appliance
Upgrade and downgrade a Citrix ADC appliance
Authentication, authorization, and auditing application traffic
Basic components of authentication, authorization, and auditing configuration
On-premises Citrix Gateway as an identity provider to Citrix Cloud
Authentication, authorization, and auditing configuration for commonly used protocols
Troubleshoot authentication and authorization related issues
-
-
-
-
-
Domain Name System
-
Persistence and persistent connections
Advanced load balancing settings
Gradually stepping up the load on a new service with virtual server–level slow start
布鲁泰克t applications on protected servers against traffic surges
Retrieve location details from user IP address using geolocation database
Use source IP address of the client when connecting to the server
Use client source IP address for backend communication in a v4-v6 load balancing configuration
Set a limit on number of requests per connection to the server
Configure automatic state transition based on percentage health of bound services
Use case 2: Configure rule based persistence based on a name-value pair in a TCP byte stream
Use case 3: Configure load balancing in direct server return mode
Use case 6: Configure load balancing in DSR mode for IPv6 networks by using the TOS field
Use case 7: Configure load balancing in DSR mode by using IP Over IP
Use case 10: Load balancing of intrusion detection system servers
Use case 11: Isolating network traffic using listen policies
Use case 12: Configure Citrix Virtual Desktops for load balancing
Use case 13: Configure Citrix Virtual Apps for load balancing
Use case 14: ShareFile wizard for load balancing Citrix ShareFile
Use case 15: Configure layer 4 load balancing on the Citrix ADC appliance
-
-
-
Authentication and authorization for System Users
-
Configuring a CloudBridge Connector Tunnel between two Datacenters
Configuring CloudBridge Connector between Datacenter and AWS Cloud
Configuring a CloudBridge Connector Tunnel Between a Datacenter and Azure Cloud
Configuring CloudBridge Connector Tunnel between Datacenter and SoftLayer Enterprise Cloud
Configuring a CloudBridge Connector Tunnel Between a Citrix ADC Appliance and Cisco IOS Device
CloudBridge Connector Tunnel Diagnostics and Troubleshooting
这个内容是机器翻译的动力ly.
Dieser Inhalt ist eine maschinelle Übersetzung, die dynamisch erstellt wurde.(Haftungsausschluss)
Cet article a été traduit automatiquement de manière dynamique.(Clause de non responsabilité)
埃斯特危象lo ha traducido una变化形式dinámica.(Aviso legal)
此内容已经过机器动态翻译。放弃
このコンテンツは動的に機械翻訳されています。免責事項
이 콘텐츠는 동적으로 기계 번역되었습니다.책임 부인
Este texto foi traduzido automaticamente.(Aviso legal)
Questo contenuto è stato tradotto dinamicamente con traduzione automatica.(Esclusione di responsabilità))
This article has been machine translated.
Dieser Artikel wurde maschinell übersetzt.(Haftungsausschluss)
Ce article a été traduit automatiquement.(Clause de non responsabilité)
Este artículo ha sido traducido automáticamente.(Aviso legal)
この記事は機械翻訳されています.免責事項
이 기사는 기계 번역되었습니다.책임 부인
Este artigo foi traduzido automaticamente.(Aviso legal)
这篇文章已经过机器翻译.放弃
Questo articolo è stato tradotto automaticamente.(Esclusione di responsabilità))
Translation failed!
Domain Name System
Note:From release 13.0 build 41.x, the Citrix ADC appliance in ADNS and proxy mode is fully compliant with DNS flag day 2019.
You can configure the Citrix ADC appliance to function as an authoritative domain name server (ADNS server) for a domain. Add the DNS resource records that belong to the domain for which the appliance is authoritative and configure resource record parameters. You can also configure the appliance as a proxy DNS server that load balances a farm of DNS name servers that are either within or outside your network. Configure the appliance as an end resolver and forwarder. You can configure DNS suffixes that enable name resolution when fully qualified domain names are not configured. The appliance also supports the DNS ANY query that retrieves all the records that belong to a domain.
You can configure the appliance to concurrently function as an authoritative DNS server for one domain and a DNS proxy server for another domain. When you configure the appliance as the authoritative DNS server or DNS proxy server for a zone, you can enable the appliance to use the TCP for response sizes that exceed the size limit specified for the User Datagram Protocol (UDP).
How DNS Works on the Citrix ADC
You can configure the Citrix ADC appliance to function as an ADNS server, DNS proxy server, end resolver, and forwarder. You can add DNS resource records on the Citrix ADC appliance, including the following records:
- Service (SRV) records
- IPv6 (AAAA) records
- Address (A) records
- Mail exchange (MX) records
- Canonical name (CNAME) records
- Pointer (PTR) records
- Start of authority (SOA) records
- Text (TXT) records
Also, you can configure the Citrix ADC to load balance external DNS name servers.
The Citrix ADC appliance can be configured as the authority for a domain. Add valid SOA and NS records for the domain.
An ADNS server is a DNS server that contains complete information about a zone.
To configure the Citrix ADC appliance as an ADNS server for a zone, you must add an ADNS service, and then configure the zone. To do so, you add valid SOA and NS records for the domain. When a client sends a DNS request, the Citrix ADC appliance searches the configured resource records for the domain name. You can configure the ADNS service to be used with the Citrix ADC Global Server Load Balancing (GSLB) feature.
You can delegate a subdomain, by adding NS records for the subdomain to the zone of the parent domain. You can then make the Citrix ADC authoritative for the subdomain, by adding a “glue record” for each of the subdomain name servers. If GSLB is configured, the Citrix ADC makes a GSLB load balancing decision based on its configuration and replies with the IP address of the selected virtual server. The following figure shows the entities in an ADNS GSLB setup and a DNS proxy setup.
Figure 1. DNS Proxy Entity Model
The Citrix ADC appliance can function as a DNS proxy. Caching of DNS records, which is an important function of a DNS proxy, is enabled by default on the Citrix ADC appliance. Caching enables the Citrix ADC appliance to provide quick responses for repeated translations. Create a load balancing DNS virtual server, and DNS services, and then bind these services to the virtual server.
The Citrix ADC provides two options, minimum time to live (TTL) and maximum TTL for configuring the lifetime of the cached data. The cached data times out as specified by your settings for these two options. The Citrix ADC checks the TTL of the DNS record coming from the server. If the TTL is less than the configured minimum TTL, it is replaced with the configured minimum TTL. If the TTL is greater than the configured maximum TTL, it is replaced with the configured maximum TTL.
The Citrix ADC also allows caching of negative responses for a domain. A negative response indicates that information about a requested domain does not exist, or that the server cannot provide an answer for the query. The storage of this information is callednegative caching. Negative caching helps speed up responses to queries on a domain, and can optionally provide the record type.
A negative response can be one of the following:
- NXDOMAIN error message - If a negative response is present in the local cache, the Citrix ADC returns an error message (NXDOMAIN). If the response is not in the local cache, the query is forwarded to the server, and the server returns an NXDOMAIN error to the Citrix ADC. The Citrix ADC caches the response locally, then returns the error message to the client.
- NODATA error message - The Citrix ADC sends a NODATA error message, if the domain name in query is valid but records of the given type are not available.
The Citrix ADC supports recursive resolution of DNS requests. In recursive resolution, the resolver (DNS client) sends a recursive query to a name server for a domain name. If the queried name server is authoritative for the domain, it responds with the requested domain name. Otherwise, the Citrix ADC queries the name servers recursively until the requested domain name is found.
Before you can apply the recursive query option, you must first enable it. You can also set the number of times the DNS resolver must send a resolution request (DNS retries) if a DNS lookup fails.
You can configure the Citrix ADC as a DNS forwarder. A forwarder passes DNS requests to external name servers. The Citrix ADC allows you to add external name servers and provides name resolution for domains outside the network. The Citrix ADC also allows you to set the name lookup priority to DNS or Windows Internet Name Service (WINS).
Enable the ADC appliance to use DNS to resolve the host name to its respective IP address
Note:You require an SSH utility to access the command line interface (CLI) of the appliance.
By default, the ADC appliance cannot resolve the host name to its respective IP address. Complete the following tasks to enable the name resolution on the appliance:
- Define name servers.
- Define a DNS suffix.
Points to note
Perform the DNS lookup from the CLI. DNS lookups from the shell prompt of the FreeBSD operating system fail because the entry in the /etc/resolv.conf file points to the 127.0.0.2 IP address.
The following commands are not available in the CLI of the appliance:
- host - dig - getent/MIP - nslookup
If the appliance cannot ping the DNS server on its SNIP address, the server status shows as down. Successful ping is important when the appliance is behind a firewall.
CLI configuration
At the command prompt, type:
add dns nameServer add dns suffix
To verify the configuration, type:
show dns nameServer show dns suffix
To test DNS resolution, type:
show dns addrec
GUI configuration
- Navigate toTraffic Management > DNS > Names Servers > Add.
- In theCreate Name Serverdialog box enter the name server IP Address and clickCreate.
- Navigate toTraffic Management > DNS > DNS Suffix > Add.
- In theCreate DNS Suffixdialog box, enter the DNS Suffix, such as example.com, to be used for all host queries and clickCreate.
Round Robin DNS
当客户端发送一个DNS请求DNSresource record, it receives a list of IP addresses resolving to the name in the DNS request. The client then uses one of the IP addresses in the list, generally, the first record or IP address. Hence, a single server is used for the total TTL of the cache and is overloaded when many requests arrive.
When the Citrix ADC receives a DNS request, it responds by changing the order of the list of DNS resource records in a round robin method. This feature is calledround robin DNS. Round robin distributes the traffic equally between data centers. The Citrix ADC performs this function automatically. You do not have to configure this behavior.
Functional Overview
If the Citrix ADC is configured as an ADNS server, it returns the DNS records in the order in which the records are configured. When the Citrix ADC is configured as a DNS proxy, it returns the DNS records in the order in which it receives the records from the server. The order of the records present in the cache matches the order in which records are received from the server.
The Citrix ADC then changes the order in which records are sent in the DNS response in a round robin method. The first response contains the first record in sequence, the second response contains the second record in sequence, and the order continues in the same sequence. Thus, clients requesting the same name can connect to different IP addresses.
Round Robin DNS Example
As an example of round robin DNS, consider DNS records that have been added as follows:
add dns addRec ns1 1.1.1.1 add dns addRec ns1 1.1.1.2 add dns addRec ns1 1.1.1.3 add dns addRec ns1 1.1.1.4
The domain, abc.com is linked to an NS record as follows:
add dns nsrec abc.com. ns1
When the Citrix ADC receives a query for the A record of ns1, the Address records are served in a round robin method as follows. In the first DNS response, 1.1.1.1 is served as the first record:
ns1. 1H IN A 1.1.1.1 ns1. 1H IN A 1.1.1.2 ns1. 1H IN A 1.1.1.3 ns1. 1H IN A 1.1.1.4
In the second DNS response, the second IP address, 1.1.1.2 is served as the first record:
ns1. 1H IN A 1.1.1.2 ns1. 1H IN A 1.1.1.3 ns1. 1H IN A 1.1.1.4 ns1. 1H IN A 1.1.1.1
In the third DNS response, the third IP address, 1.1.1.2 is served as the first record:
ns1. 1H IN A 1.1.1.3 ns1. 1H IN A 1.1.1.4 ns1. 1H IN A 1.1.1.1 ns1. 1H IN A 1.1.1.2
Share
Share
This Preview product documentation is Citrix Confidential.
You agree to hold this documentation confidential pursuant to the terms of your Citrix Beta/Tech Preview Agreement.
开发、发布和时间的功能s or functionality described in the Preview documentation remains at our sole discretion and are subject to change without notice or consultation.
The documentation is for informational purposes only and is not a commitment, promise or legal obligation to deliver any material, code or functionality and should not be relied upon in making Citrix product purchase decisions.
If you do not agree, select Do Not Agree to exit.