On 4/5/22 14:16, Dincer Beken wrote: > Hello, > > On the GTP-U implementation in the userspace, I see that the IP Header > Identification Field is not set in the encapsulated packets. This is not like > this in the Kernel Implementation. I don't get replies when I send these > tunneled packets. > > From the Specification, I see that this fiedl should be unique within a > window. > > Does anybody have an idea about this?
I'm not an expert, but AFAICT, IP Header Identification Field is mainly used when IP fragmentation is happening. In other cases it remains zero. OVS will use DF (DontFrag) IP flag by default for the outer header, so the packet should not be fragmented later. However, that may mean that if MTU is not uniform in your network, the packet over the MTU can be dropped. You may look for ICMP 'need to frag' replies in your network. Make sure that your interfaces has enough MTU to accommodate the extra GTP-U header. Or you may try setting 'options:df_default=false' for the tunnel port, but it seems to be a bad practice to allow fragmentation of tunnel packets. > > Regards, > Dincer > > > > > *Dincer Beken* > Software Developer > > t: +49 8331 99 59-852 <tel:+49 8331 99 59-852> > > e: [email protected] <mailto:[email protected]> > w: https://blackned.de <https://blackned.de> > > > > > <https://www.linkedin.com/company/8960382> > > > > > blackned GmbH · zugspitzstraße 1 · 87751 heimertingen > geschäftsführer: timo haas · hrb memmingen 17319 > > Diese eMail enthält vertrauliche und/oder rechtlich geschützte Informationen. > Wenn Sie nicht der richtige Adressat sind oder diese eMail irrtümlich > erhalten haben, informieren Sie bitte sofort den Absender und löschen Sie > diese eMail. > Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser eMail ist nicht > gestattet. > > This eMail may contain confidential and/or privileged information. > If you are not the intended recipient (or have received this eMail in error) > please notify the sender immediately and delete this eMail. > Any unauthorized copying, disclosure or distribution of the contents in this > eMail is strictly forbidden. > _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
