PPoe public ip address always change

Hi i encountered issue on NSF firewall the wan ppoe public adress always change when we connect and disconnect what would be the reason


any idea

Hi,

It is normal for PPPoE connections to have dynamic IP addresses that change frequently. This is because PPPoE is a protocol that allows the ISP to dynamically assign IP addresses to the user’s device when it connects to the internet.

excerpt from the web...

PPPoE is a network protocol used to encapsulate PPP (Point-to-Point Protocol) frames inside Ethernet frames. It combines the PPP that owns the function of authentication and encryption, and the Ethernet protocol that can support multiple users in a LAN.

PPPoE is what lets your computer talk to your modem over an Ethernet network. Dynamic and static IP addresses are related concepts. Typically, your needs an IP address in order to connect to the Internet. If you have a static IP address, it means there's an IP address reserved for you, and no matter how many times you connect and disconnect, you'll always get that same address. If you have a dynamic IP address, it means that someone is going to assign you an IP address (usually your ISP), and usually they'll have a pool of IP addresses set aside, and will just give you a random one from that pool.

it works with dynamic IP which keep changing every now and then.

The dynamic change in the PPPoE public IP address on your NS firewall when connecting and disconnecting is likely a result of your Internet Service Provider's (ISP) configuration. PPPoE connections often use dynamic IP addressing, where the ISP assigns a new public IP address each time the connection is established. This dynamic allocation can be a standard practice to manage IP address resources efficiently. To address this issue, you may want to check with your ISP if they offer a static IP option for PPPoE connections, or consider using a dynamic DNS service to maintain consistent access to your network resources despite the changing public IP address.

Dynamic IP Will change for PPoE, to solve this use static Public IP or Have DDNS.

Hope this Helps!

Hi, you have to ask your provider to give you at least one static public ip to use.

A Sangfor NSF firewall experiencing frequent WAN PPPoE public address changes upon connection and disconnection can be caused by several factors. Here are some potential reasons and troubleshooting steps:

Possible Reasons:

    ISP Configuration:
        Dynamic IP Allocation: Your internet service provider (ISP) might assign dynamic IP addresses through PPPoE, leading to frequent changes.
        Lease Timeout: The assigned IP address lease might have a short expiration time, triggering automatic renewal and change.

    Firewall Configuration:
        PPPoE Reconnect Settings: The firewall's PPPoE reconnect settings might be overly aggressive, causing frequent disconnects and reconnects with new IP addresses.
        DNS Dynamic Update: If enabled, dynamic DNS updates based on the changing IP address can further complicate troubleshooting.

    Technical Issues:
        Modem Instability: Faulty or unstable modem hardware can trigger disconnects and reconnects with new IP addresses.
        Network Congestion: Heavy network traffic might lead to temporary connection losses and subsequent re-establishment with new IPs.

Troubleshooting Steps:

    Verify ISP Configuration:
        Contact your ISP to confirm if they assign dynamic IP addresses through PPPoE.
        Inquire about the IP address lease duration and renewal process.

    Review Firewall Settings:
        Access the Sangfor NSF firewall's web console.
        Navigate to the PPPoE configuration section.
        Check the reconnect settings and adjust them if necessary. For example, increase the reconnect interval to avoid overly frequent attempts.
        Disable dynamic DNS updates if not required.

    Investigate Technical Issues:
        Check the modem's logs for any error messages or disconnection events.
        Consider restarting the modem or contacting your ISP for further technical assistance.
        Monitor network traffic to identify potential congestion issues.

    Additional Tips:
        Document the observed IP address changes and their timestamps for further analysis.
        Consider setting up static PPPoE configuration with your ISP if consistent IP address access is crucial.
        Consult the Sangfor NSF firewall documentation or contact Sangfor support for specific troubleshooting guidance based on your model and firmware version.

Some ISPs (Internet Service Providers) use dynamic IP address assignment for PPPoE connections. In this case, your public IP address can change each time you establish a new PPPoE connection. Check with your ISP to confirm whether they use dynamic or static IP addressing for your PPPoE connection.

The ISP may have configured their systems to provide dynamic IP addresses to PPPoE connections. If this is the case, you might need to contact your ISP to inquire about the possibility of obtaining a static IP address if your requirements demand a consistent public IP.