Re: [opennhrp-devel] <multicast nhs> setting in opennhrp.conf for OSPF over mGRE

[Frank M. <fr...@kl...>]

Hi Timo,
I had a look a the options for the <multicast ...> config option in opennhrp.c which looks as below. Do you know how config options other than 'nhs' work? Maybe I need to set a protocol address?



Frank

###############################
} else if (strcmp(word, "multicast") == 0) {
                        NEED_INTERFACE();
                        read_word(in, &lineno, sizeof(word), word);
                        if (strcmp(word, "dynamic") == 0) {
                                iface->mcast_mask = \
                                        BIT(NHRP_PEER_TYPE_STATIC) |
                                        BIT(NHRP_PEER_TYPE_DYNAMIC_NHS) |
                                        BIT(NHRP_PEER_TYPE_DYNAMIC);
                        } else if (strcmp(word, "nhs") == 0) {
                                iface->mcast_mask = \
                                        BIT(NHRP_PEER_TYPE_STATIC) |
                                        BIT(NHRP_PEER_TYPE_DYNAMIC_NHS);
                        } else if (nhrp_address_parse(word, &paddr, NULL)) {
                                iface->mcast_numaddr++;
                                iface->mcast_addr = realloc(iface->mcast_addr,
                                        iface->mcast_numaddr *
                                        sizeof(struct nhrp_address));
                                iface->mcast_addr[iface->mcast_numaddr-1] =
                                        paddr;
                        } else {
                                rc = 6;
                                break;
############################


On 13 Dec 2010, at 11:18, Timo Teräs wrote:

> On 12/10/2010 02:17 PM, Frank Murray wrote:
>> I have the test network below:
>> 
>> (eth0:192.168.1.1/24) OpenNHRP Spoke (eth1:192.168.2.2/24)
>> ---->(192.168.2.1) Cisco Intermediate (192.168.3.1) ------> 
>> 
>> (192.168.3.2) Cisco Hub (192.168.4.0/24).
>> 
>> I've greated an mGRE tunnel from the Spoke (10.0.0.2) to the Cisco hub
>> (10.0.0.1) and the GRE tunnel comes up and I can ping the GRE address of
>> the Cisco from the Linux box. I want to run OSPF over the link so I've
>> added Quagga and enabled OSPF. In the network above the OSPF updates are
>> sent by the spoke to an Ethernet address of 01:00:5e:00:00:05 rather
>> than the MAC address of 192.168.2.1 on the Cisco Intermediate router and
>> are therefore ignored. How do I manipulate the multicast setting to send
>> them to a unicast MAC address?
>> 
>> Note that removing the Intermediate router and setting <multicast nhs>
>> in tunnel config allows mGRE to create the tunnel successfully and
>> Quagga to send OSPF updates over it.
>> 
>> Here is the 
>> opennhrp.conf
>> ----------------------
>> interface tgre0
>>  holding-time 7200 
>>  map 10.0.0.1/24 192.168.3.2 register cisco #tgre0
>>  cisco-authentication test 
>>  multicast nhs
>>  shortcut 
>>  redirect 
>>  non-caching 
>> 
>> 
>> Grateful for any help,
> 
> I'm not entirely sure what the problem is. OSPF packets are multicast,
> and should not be sent to unicast address. So sounds like there's
> something wrong in some part of your setup; the multicast packets should
> be sent out.
> 
> One thing to check is how you create the gre tunnel? You should
> explicitly specify the 'ttl' argument and set it to 64 or some other
> reasonable value. If not specified, it defaults to "inherit". Which
> would be problem with OSPF since it sets TTL=1 -- meaning that the
> packets will not traverse through additional routers.
> 
> - Timo