My little guy, also 6.5 months, was having same problem. We fixed the problem, though he is waking early right now because he got sick.
1. Make sure it's not hunger, if not then try these things
2. Looks like the baby is up too long at night before bed. So for the next few nights put the baby to bed 2 hours after up from last nap to overcome any over tiredness. So if baby wakes at 3 from last nap put to bed at 5 or 5:30. Sounds strange but our little guy actually only woke once the first night we did this.
3. Give a quick nap at night before bed to prevent over tiredness. If you want to keep bedtime at 7 then a 30 min nap at 4:30 is good.
We had to put out little guy to bed at 5 for 2 nights while doing the other settling method, and even though he is waking a little earlier, which we are trying to extend longer again, he is sleeping thru night, which makes a big diff for mommy and daddy sleep!