explain the difference between subinterfaces and vlan interfaces on ngaf 10

explain the difference between subinterfaces and vlan interfaces on ngaf

HiHi,

Please refer to the attached link for the Sangfor NGAF Interface Description,

specifically focusing on sections 3.6 Sub-Interface and 3.7 VLAN Interface description.

SANGFOR_NGAF_v8.0.5_Interface_Description link.pdf (66.31 KB, Downloads: 71)

20 May 2024 17:21 Upload

Click file name to download attachment

Sub Interface is logical interface, function interface same as vlan, but sub interface used when the Primary interface (eth) set as Layer3
vlan used when interface (eth) set as Layer2

Hi, here's the difference between subinterfaces and VLAN interfaces on Sangfor NGAF.

Subinterfaces: These are logical interfaces that are established on a router’s physical interface. With Sangfor NGAF, you have the ability to create several subinterfaces under a single LAN layer 3 interface and assign them appropriate VLAN numbers. Each subinterface is part of a unique Layer 3 network and can be assigned its own IP address, enabling inter-VLAN routing. This setup is often referred to as a router-on-a-stick configuration.

VLAN Interfaces: These interfaces are established for VLANs and serve as the Layer 3 gateway for the VLAN. In Sangfor NGAF, you can establish a Layer 2 (Bridge) interface, designate the link type as TRUNK, and specify the permitted VLAN (for example, VLAN 2-10). Following this, you can create VLAN interfaces, assign IP addresses, and set VLAN numbers. Each VLAN interface is part of a unique Layer 2 network and can be assigned its own IP address.

To summarize, both subinterfaces and VLAN interfaces facilitate network segmentation and inter-VLAN routing. However, the primary distinction lies in the layer at which they function. Subinterfaces function at Layer 3 (the network layer) and are typically utilized in router-on-a-stick configurations, whereas VLAN interfaces function at Layer 2 (the data link layer) and are typically utilized in switch-based network configurations.

Hi,

The difference between the two is that the switch virtual interace of SVI is bound to a VLAN used for Layer 2 switching, while a sub-interface is part of an Layer 3 interface that doesn't take part in Layer 22 switching. Similarly, a specific VLAN ID on a sub-interface may indicate a different VLAN than the same VLID on another interface.

I think this topic is not related to FW but to switches:

Subinterfaces and VLAN interfaces on a Next-Generation Firewall (NGAF) serve distinct purposes but are related to network segmentation. A subinterface is a logical division of a physical interface, allowing it to handle multiple networks by tagging traffic with different VLAN IDs.

Hi,

Subinterfaces and VLAN interfaces (SVIs) are used for network segmentation and routing but differ in application and configuration.

Subinterfaces are virtual interfaces on a router's physical interface, allowing it to handle traffic for multiple VLANs via 802.1Q tagging. Each subinterface has its own IP and VLAN ID, facilitating Inter-VLAN routing.

SVIs are logical interfaces on a Layer 3 switch, representing a VLAN. They enable Layer 3 routing within a VLAN, allowing inter-VLAN communication without an external router. SVIs are configured directly as VLAN interfaces, providing IP routing for the VLAN.

Hi,
Both subinterfaces and VLAN interfaces on NGAF (Next Generation Application Firewall) are used for network segmentation, but they function at different layers of the OSI model:

VLAN Interfaces (SVI - Switched Virtual Interface):

Layer 2 (Data Link Layer) construct.
Binds to a specific VLAN ID.
Acts like a separate Layer 2 switch port, participating in L2 switching within that VLAN.
Traffic on the VLAN interface sees all other devices within the same VLAN.
Useful for creating isolated broadcast domains for different network segments.
Subinterfaces:

Layer 3 (Network Layer) construct.
Created on top of a physical interface.
Identified by a combination of the physical interface name and a VLAN ID (e.g., eth0.10 for VLAN 10 on eth0).
Functions as a separate IP interface, allowing independent routing and security policies for each VLAN.
Traffic on a subinterface is unaware of other devices on the same physical interface but belonging to different VLANs.
Used for connecting a single physical interface to multiple VLANs, enabling communication between VLANs at Layer 3.
Here's an analogy:

VLAN interfaces are like separate virtual rooms within a building (Layer 2). Devices in the same room can see and interact with each other.
Subinterfaces are like individual offices within a room (Layer 3). People in each office can't directly see each other but can communicate through hallways (routing) if needed.

VLAN interface is for Layer 2 interfaces
Sub-interface is layer 3 interface

describtion
Vlan Interface = if you make multiply layer 2 interfaces then you have to make vlan interface, and you have options that you can shift the cables to another layer2 interface without changes in vlan interface

Sub-interface is created your interface is layer 3 link. and you have to created it on particular interface

H

ere's the breakdown of the key differences between subinterfaces and VLAN interfaces on Sangfor NGAF:

Layer:

    Subinterface: Operates at Layer 3 (Network)
    VLAN Interface: Operates at Layer 2 (Data Link)

Function:

    Subinterface: Creates a logical Layer 3 interface on top of a physical interface. This allows assigning a unique IP address to each VLAN carried by the physical interface. It facilitates routing between VLANs. (Think of it like creating multiple virtual routers on a single physical port)
    VLAN Interface: Represents a specific VLAN on a physical switch port. It doesn't have its own IP address and primarily functions for Layer 2 switching within the VLAN. (Think of it as carving out dedicated lanes for different VLANs on a single highway)

Use Cases:

    Subinterface: Used in "router on a stick" scenarios where a single physical interface carries traffic for multiple VLANs. Ideal for situations where you need to route between VLANs on the Sangfor NGAF device.
    VLAN Interface: Used for connecting the Sangfor NGAF to a switch where VLANs are already configured. These interfaces allow the NGAF to participate in Layer 2 switching within each VLAN.

Analogy:

Imagine an apartment building (physical interface). Subinterfaces are like creating virtual apartments (each with its own address) within the building to house different tenants (VLANs). VLAN interfaces are like designating specific floors (VLANs) within the building for tenants to reside.