Spanning Tree Protocol (STP) in NetScaler Appliance

來源 https://support.citrix.com/article/CTX112341

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Information

This contains information about Spanning Tree Protocol (STP) in the NetScaler Appliance.

Spanning Tree Protocol

STP is a link layer network protocol used to avoid Layer 2 loops (bridge loops) which is commonly used on network switches. The best practice is to disable STP on the interfaces that are connected to the NetScaler appliance because STP can interfere with proper operation during 30 to 50 seconds that the ports are in the LISTENING or LEARNING states. For instance, while the switch ports are in Listening/Learning states:

• The NetScaler appliances that are in a High Availability (HA) setup cannot receive HA heartbeats from their neighbor, which results in both nodes going into the PRIMARY state.
• The NetScaler appliance might reset its interfaces to resolve an interface problem. It resets the port back to LISTENING state on the switch and this cycle could continue forever.
• ARPs and GARPs might be lost, interfering with the operation between the primary and secondary appliances.

With L2 mode disabled (the default setting), the appliance does not switch packets between interfaces in the same virtual LAN, a layer 2 loop cannot exist. Therefore, enabling STP on the interfaces connected to the appliance is not necessary. However, if it is a requirement to enable STP on the ports connected to the appliance, configure Rapid Spanning Tree Protocol (RSTP),to resolve the preceding issues.

In cases where L2 mode on the appliance should be enabled, you must consider the following aspects:

• The NetScaler appliances do not participate in the spanning tree.
• With mode Bridge BPDUs: OFF (the default mode), or with older NetScaler software releases that did not have the Bridge BPDUs mode as an option, the NetScaler appliance drops all BPDUs received on an interface.
• With L2 mode enabled, the appliance switches other frames (such as broadcasts) between two interfaces configured in and connected to the same VLAN.

When you consider the preceding aspects, it could lead to a switching loop that spanning tree might not be able to resolve. You must ensure that a loop-free network at layer 2 before enabling L2 mode. Additionally, if L2 mode is a requirement, it is recommended to ensure that the NetScaler software release installed on the appliance includes the Bridge BPDUs mode in the ON state.

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資訊

其中包含有關NetScaler Appliance中生成樹協議（STP）的資訊。

生成樹協議

STP是一種鏈路層網路協議，用於避免在網路交換機上常用的第2層環路（網橋環路）。最佳做法是在連線到NetScaler裝置的介面上禁用STP，因為STP可能會在埠處於“收聽”或“學習”狀態的30到50秒內干擾正常操作。例如，當交換機埠處於偵聽/學習狀態時：

• 處於高可用性（HA）設定的NetScaler裝置無法從其鄰居接收HA心跳，這導致兩個節點都進入PRIMARY狀態。
• NetScaler裝置可能會重置其介面以解決介面問題。它將埠重置為交換機上的LISTENING狀態，此迴圈可以永久持續。
• ARP和GARP可能會丟失，從而干擾主裝置和輔助裝置之間的操作。

禁用L2模式（預設設定）後，裝置不會在同一虛擬LAN中的介面之間切換資料包，不能存在第2層環路。因此，無需在連線到裝置的介面上啟用STP。但是，如果要求在連線到裝置的埠上啟用STP，請配置快速生成樹協議（RSTP）以解決上述問題。

如果應啟用裝置上的L2模式，則必須考慮以下方面：

• NetScaler裝置不參與生成樹。
• 對於模式橋接BPDU：OFF（預設模式），或者沒有選擇Bridge BPDU模式的舊NetScaler軟體版本，NetScaler裝置會丟棄介面上收到的所有BPDU。
• 啟用L2模式後，裝置會在配置並連線到同一VLAN的兩個介面之間切換其他幀（例如廣播）。

當您考慮前面的方面時，它可能會導致生成樹可能無法解析的切換迴圈。在啟用L2模式之前，必須確保第2層的無環路網路。此外，如果需要L2模式，建議確保裝置上安裝的NetScaler軟體版本包含處於ON狀態的Bridge BPDU模式。

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NetScaler 整合的 ZebOS 網路模組。

ZebOS 7.8.1 support Protocol Daemons
Each routing and switching protocol supported in the ZebOS suite runs in a separate daemon, built from individual source files. Code updates, patches and enhancements are applied on a module-by-module basis without disrupting other running protocols. The following table lists the daemon file names for the operating systems (OS) supported by ZebOS. No indicates that a protocol is not supported for an OS.

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